How to use custom item modifier in 24w10a

to clarify  what I mean by custom item modifier:
item modify entity @s weapon.mainhand [custom item modifier]
Before it worked like this:
              "function": "minecraft:set_nbt",
              "tag": "{ChargedProjectiles:[{id:\"minecraft:arrow\",Count:1b}],Charged:1b}"
            }```
Folder Path being:
 datapacks/[datapack name]/data/[custom name]/item_modifiers/[custom item modifier].json

Now I tried it like this:
```            {
              "function": "minecraft:set_nbt",
              "tag": "[minecraft:charged_projectiles=[{id:\"arrow\"}]]"
            } ```

Using the same folder path but it doesnt work, tried a few things but none worked.