No vegetation

No vegetation in my biome.

If needed, here's the code.

package net.mcreator.amethyst.world.biome;

import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
import net.minecraftforge.fml.event.lifecycle.FMLCommonSetupEvent;
import net.minecraftforge.eventbus.api.SubscribeEvent;
import net.minecraftforge.event.RegistryEvent;
import net.minecraftforge.common.BiomeManager;
import net.minecraftforge.common.BiomeDictionary;

import net.minecraft.world.gen.trunkplacer.MegaJungleTrunkPlacer;
import net.minecraft.world.gen.treedecorator.TrunkVineTreeDecorator;
import net.minecraft.world.gen.treedecorator.LeaveVineTreeDecorator;
import net.minecraft.world.gen.surfacebuilders.SurfaceBuilderConfig;
import net.minecraft.world.gen.surfacebuilders.SurfaceBuilder;
import net.minecraft.world.gen.placement.Placement;
import net.minecraft.world.gen.placement.NoiseDependant;
import net.minecraft.world.gen.placement.AtSurfaceWithExtraConfig;
import net.minecraft.world.gen.foliageplacer.JungleFoliagePlacer;
import net.minecraft.world.gen.feature.structure.StructureFeatures;
import net.minecraft.world.gen.feature.TwoLayerFeature;
import net.minecraft.world.gen.feature.ProbabilityConfig;
import net.minecraft.world.gen.feature.Features;
import net.minecraft.world.gen.feature.FeatureSpread;
import net.minecraft.world.gen.feature.Feature;
import net.minecraft.world.gen.feature.BlockClusterFeatureConfig;
import net.minecraft.world.gen.feature.BigMushroomFeatureConfig;
import net.minecraft.world.gen.feature.BaseTreeFeatureConfig;
import net.minecraft.world.gen.blockstateprovider.SimpleBlockStateProvider;
import net.minecraft.world.gen.blockplacer.SimpleBlockPlacer;
import net.minecraft.world.gen.GenerationStage;
import net.minecraft.world.biome.MobSpawnInfo;
import net.minecraft.world.biome.DefaultBiomeFeatures;
import net.minecraft.world.biome.BiomeGenerationSettings;
import net.minecraft.world.biome.BiomeAmbience;
import net.minecraft.world.biome.Biome;
import net.minecraft.util.registry.WorldGenRegistries;
import net.minecraft.util.registry.Registry;
import net.minecraft.util.RegistryKey;
import net.minecraft.block.HugeMushroomBlock;
import net.minecraft.block.Blocks;

import net.mcreator.amethyst.block.AmethystGrassBlock;
import net.mcreator.amethyst.AmethystModElements;

import com.google.common.collect.ImmutableList;

@AmethystModElements.ModElement.Tag
public class AmethystStreetBiome extends AmethystModElements.ModElement {
    public static Biome biome;
    public AmethystStreetBiome(AmethystModElements instance) {
        super(instance, 23);
        FMLJavaModLoadingContext.get().getModEventBus().register(new BiomeRegisterHandler());
    }
    private static class BiomeRegisterHandler {
        @SubscribeEvent
        public void registerBiomes(RegistryEvent.Register<Biome> event) {
            if (biome == null) {
                BiomeAmbience effects = new BiomeAmbience.Builder().setFogColor(12638463).setWaterColor(-10092391).setWaterFogColor(329011)
                        .withSkyColor(7972607).withFoliageColor(-10092442).withGrassColor(-10092442).build();
                BiomeGenerationSettings.Builder biomeGenerationSettings = new BiomeGenerationSettings.Builder()
                        .withSurfaceBuilder(SurfaceBuilder.DEFAULT.func_242929_a(new SurfaceBuilderConfig(AmethystGrassBlock.block.getDefaultState(),
                                Blocks.DIRT.getDefaultState(), Blocks.DIRT.getDefaultState())));
                biomeGenerationSettings.withStructure(StructureFeatures.MINESHAFT);
                biomeGenerationSettings.withFeature(GenerationStage.Decoration.VEGETAL_DECORATION, Feature.TREE
                        .withConfiguration((new BaseTreeFeatureConfig.Builder(new SimpleBlockStateProvider(Blocks.JUNGLE_LOG.getDefaultState()),
                                new SimpleBlockStateProvider(Blocks.JUNGLE_LEAVES.getDefaultState()),
                                new JungleFoliagePlacer(FeatureSpread.func_242252_a(2), FeatureSpread.func_242252_a(0), 2),
                                new MegaJungleTrunkPlacer(10, 2, 19), new TwoLayerFeature(1, 1, 2)))
                                        .setDecorators(
                                                ImmutableList.of(TrunkVineTreeDecorator.field_236879_b_, LeaveVineTreeDecorator.field_236871_b_))
                                        .build())
                        .withPlacement(Features.Placements.HEIGHTMAP_PLACEMENT)
                        .withPlacement(Placement.COUNT_EXTRA.configure(new AtSurfaceWithExtraConfig(1, 0.1F, 1))));
                biomeGenerationSettings.withFeature(GenerationStage.Decoration.VEGETAL_DECORATION,
                        Feature.RANDOM_PATCH.withConfiguration(Features.Configs.GRASS_PATCH_CONFIG).withPlacement(Features.Placements.PATCH_PLACEMENT)
                                .withPlacement(Placement.COUNT_NOISE.configure(new NoiseDependant(-0.8D, 5, 4))));
                biomeGenerationSettings.withFeature(GenerationStage.Decoration.VEGETAL_DECORATION, Feature.SEAGRASS
                        .withConfiguration(new ProbabilityConfig(0.3F)).func_242731_b(1).withPlacement(Features.Placements.SEAGRASS_DISK_PLACEMENT));
                biomeGenerationSettings.withFeature(GenerationStage.Decoration.VEGETAL_DECORATION,
                        Feature.FLOWER.withConfiguration(Features.Configs.NORMAL_FLOWER_CONFIG)
                                .withPlacement(Features.Placements.VEGETATION_PLACEMENT).withPlacement(Features.Placements.HEIGHTMAP_PLACEMENT)
                                .func_242731_b(2));
                biomeGenerationSettings.withFeature(GenerationStage.Decoration.VEGETAL_DECORATION,
                        Feature.RANDOM_PATCH.withConfiguration(
                                (new BlockClusterFeatureConfig.Builder(new SimpleBlockStateProvider(Blocks.BROWN_MUSHROOM.getDefaultState()),
                                        SimpleBlockPlacer.PLACER)).tries(2).func_227317_b_().build()));
                biomeGenerationSettings.withFeature(GenerationStage.Decoration.VEGETAL_DECORATION,
                        Feature.RANDOM_PATCH.withConfiguration(
                                (new BlockClusterFeatureConfig.Builder(new SimpleBlockStateProvider(Blocks.RED_MUSHROOM.getDefaultState()),
                                        SimpleBlockPlacer.PLACER)).tries(2).func_227317_b_().build()));
                biomeGenerationSettings.withFeature(GenerationStage.Decoration.VEGETAL_DECORATION,
                        Feature.HUGE_BROWN_MUSHROOM.withConfiguration(new BigMushroomFeatureConfig(
                                new SimpleBlockStateProvider(Blocks.BROWN_MUSHROOM_BLOCK.getDefaultState().with(HugeMushroomBlock.UP, Boolean.TRUE)
                                        .with(HugeMushroomBlock.DOWN, Boolean.FALSE)),
                                new SimpleBlockStateProvider(Blocks.MUSHROOM_STEM.getDefaultState().with(HugeMushroomBlock.UP, Boolean.FALSE)
                                        .with(HugeMushroomBlock.DOWN, Boolean.FALSE)),
                                4)));
                biomeGenerationSettings.withFeature(GenerationStage.Decoration.VEGETAL_DECORATION,
                        Feature.HUGE_RED_MUSHROOM.withConfiguration(new BigMushroomFeatureConfig(
                                new SimpleBlockStateProvider(Blocks.RED_MUSHROOM_BLOCK.getDefaultState().with(HugeMushroomBlock.DOWN, Boolean.FALSE)),
                                new SimpleBlockStateProvider(Blocks.MUSHROOM_STEM.getDefaultState().with(HugeMushroomBlock.UP, Boolean.FALSE)
                                        .with(HugeMushroomBlock.DOWN, Boolean.FALSE)),
                                4)));
                DefaultBiomeFeatures.withCavesAndCanyons(biomeGenerationSettings);
                DefaultBiomeFeatures.withOverworldOres(biomeGenerationSettings);
                DefaultBiomeFeatures.withFrozenTopLayer(biomeGenerationSettings);
                MobSpawnInfo.Builder mobSpawnInfo = new MobSpawnInfo.Builder().isValidSpawnBiomeForPlayer();
                biome = new Biome.Builder().precipitation(Biome.RainType.RAIN).category(Biome.Category.FOREST).depth(0.5f).scale(0.2f)
                        .temperature(1.2f).downfall(0.2f).setEffects(effects).withMobSpawnSettings(mobSpawnInfo.copy())
                        .withGenerationSettings(biomeGenerationSettings.build()).build();
                event.getRegistry().register(biome.setRegistryName("amethyst:amethyst_street"));
            }
        }
    }
    @Override
    public void init(FMLCommonSetupEvent event) {
        BiomeDictionary.addTypes(RegistryKey.getOrCreateKey(Registry.BIOME_KEY, WorldGenRegistries.BIOME.getKey(biome)), BiomeDictionary.Type.FOREST);
        BiomeManager.addBiome(BiomeManager.BiomeType.WARM,
                new BiomeManager.BiomeEntry(RegistryKey.getOrCreateKey(Registry.BIOME_KEY, WorldGenRegistries.BIOME.getKey(biome)), 15));
    }
}