I'm trying to modify the level at which we unlock the dragon loot items thanks to the levelz mod via datapacks,

But I can't differentiate the bow, the crossbow and the trident from their dragon scale forms.
Can you create a way to do it through materials as well as tools ?

This is an issue for the levelz repository :)

You can edit them via datapacks. I recommend to use the material which is "dragon"