Topic category: User side tutorials
This topic is to teach you how to make your ore spawn only in a specific biome. I don't really know is there is any functionality to do this in MCreator, but I'll show you my way to do it.
In the Events tab of your block, search the event called "On block added", then add a new procedure for this one. Call it whatever you want.
Now just place a "if" condition, and add in condition a "not" block, followed by "is biome at X Y Z type *the biome you want the ore to spawn in*". Use OR conditions and place in them every biome you want the ore to spawn in. The whole condition will detect if the ore spawned in another biome.
In the IF block, put a "place BLOCK.STONE at X Y Z". The entire procedure will replace every ore that didn't spawn in the biomes you want with regular stone (as ore always spawn in stone).
It's a very quick way, but maybe there's even quicker... don't hesitate to try it and to send me your feedback about this idea!