Hi,
The Backpacks mod adds recipes which craft backpacks with a specific UID; holding one and typing /ct hand prints this:

<backpack:backpack:200>.withTag({"backpack-UID": "10512ab0-c73e-41cc-b574-4c54bc25e36f", slots: 54, leather_tier: "III", frame_tier: "III", slots_used: 0, module_slots: 6, slots_per_row: 9})

It appears that attempting to craft one without the backpack-UID field makes it non-usable.
Is there any way of making custom crafting recipes for the mod with that requirement? Can CraftTweaker generate such UID?
Thank you!

Not really, that would require randomness (to generate a random uuid), which isn't really in CraftTweaker (it is a mission to sync things correctly).