in C:\Users\Veron Karoomi\curseforge\minecraft\Instances\Troll Craft v1\kubejs\startup_scripts
i added to the startup script folder
StartupEvents.registry('item', event => {
  event.create('dark_matter_mesh', 'createsifter:mesh')
    .displayName('Dark Matter Mesh')
    .texture("mesh", "kubejs:item/dark_matter_mesh")
    .maxDamage(1000)

  event.create('red_matter_mesh', 'createsifter:mesh')
    .displayName('Red Matter Mesh')
    .texture("mesh", "kubejs:item/red_matter_mesh")
    .maxDamage(5000)

})

than i went to C:\Users\Veron Karoomi\curseforge\minecraft\Instances\Troll Craft v1\kubejs\assets\kubejs\textures\item
and added to textures dark_matter_mesh and red_matter_mesh

than i went to C:\Users\Veron Karoomi\curseforge\minecraft\Instances\Troll Craft v1\kubejs\data\createsifter\tags\items

and added meshes.json
and in them i had

{
  "replace": false,
  "values": [
    "kubejs:dark_matter_mesh",
    "kubejs:red_matter_mesh"
  ]
}

than i went to C:\Users\Veron Karoomi\curseforge\minecraft\Instances\Troll Craft v1\kubejs\assets\kubejs\lang
and added a file called en_us.json which had 

{
  "item.kubejs.diamond_mesh": "Dark Matter Mesh",
  "item.kubejs.red_matter_mesh": "Red Matter Mesh"
}

i also did this C:\Users\Veron Karoomi\curseforge\minecraft\Instances\Troll Craft v1\kubejs\assets\kubejs\models\item
and added dark_matter_mesh.json and red_matter_mesh.json and in them where 

{
  "parent": "item/generated",
  "textures": {
    "layer0": "kubejs:item/dark_matter_mesh"
  }
}

{
  "parent": "item/generated",
  "textures": {
    "layer0": "kubejs:item/red_matter_mesh"
  }
}