Make Items bigger

I've looked around and tried some things but blockbench doesn't work and this code:

{
  "parent": "item/handheld",
  "textures": {
    "layer0": "gengar_marcs_modpack:item/a_mc_black_and_red_jester_scythe_based_on_the_youtuber_clownpierce_1_1"
  }
},
    "display": {
        "ground": {
            "rotation": [ 0, 0, 0 ],
            "translation": [ 0, 3, 0],
            "scale":[ 1, 1, 1 ]
        },
        "fixed": {
            "rotation": [ 0, 0, 0 ],
            "translation": [ 0, 0, 0],
            "scale":[ 1, 1, 1 ]
        },
        "thirdperson_righthand": {
            "rotation": [ 0, 90, 40 ],
            "translation": [ 0, 15, 2 ],
            "scale": [ 2.0, 2.0, 2.0 ]
        },
        "firstperson_righthand": {
            "rotation": [ 0, 90, 40 ],
            "translation": [ 0, 15, 2 ],
            "scale": [ 2.0, 2.0, 2.0 ]
        },
        "firstperson_lefthand": {
            "rotation": [ 0, 90, 40 ],
            "translation": [ 0, 15, 2 ],
            "scale": [ 2.0, 2.0, 2.0 ]
        }
    }

On the .JSON File doesn't do anything for some reason: https://ibb.co/3dYSsfZ

I have no Idea what to try