MCreator Projectile Item Arow Method

@Override
public AbstractArrow createArrow(Level world, ItemStack stack, LivingEntity shooter, @Nullable ItemStack firedFromWeapon)
{
    return new TestProjectileEntity(CombatAddonsModEntities.TEST_PROJECTILE.get(), shooter, world, stack);
    // "TEST_PROJECTILE" should be your projectile's registry name in SCREAMING_SNAKE_CASE (yes this is what it's called)
    // "CombatAddonsModEntities" should be your mod's name + "ModEntities"
    // You can also check this by going to the ModEntities file, accessible by opening the last listed file in any entity mod element
}