To enable applying these enchantments to any item, add the item the one or more of the following tags:

spell_power:enchantable/critical_damage
spell_power:enchantable/critical_chance
spell_power:enchantable/haste
spell_power:enchantable/spell_power_energize
spell_power:enchantable/spell_power_generic
spell_power:enchantable/spell_power_soulfrost
spell_power:enchantable/spell_power_specialized
spell_power:enchantable/spell_power_sunfire

I've tried adding tags to armor from KnightQuest this way (KubeJS):

ServerEvents.tags('item', event => {
  event.add('spell_power:enchantable/haste', 'knightquest:shinobi_helmet');
});

but that doesnt work.

KubeJS says tags have been added correctly, but I still can't add enchantment through anvil or enchantment table.

Im running 1.20.1 Forge with Sinytra Connector + Enchanting System Overhaul. Other mods here: https://pastebin.com/KZs5667k

Can you help to manage whats wrong?

UPD1: Enchantments from Spell Engine could be applied to any item only in Creative mode, but Survival, doesnt matter if tags are added or no.

Seems like should work, but it doesnt

I have Witch Hat (KnightQuest) with +4 Fire Spell Power

I've added a tag to it through KubeJS

ServerEvents.tags('item', event => {
  event.add('spell_power:enchantable/spell_power_sunfire', 'knightquest:witch_helmet');
});

But I still cant add a Sunfire enchantment via anvil or ench. table

On 1.20.1 there tags are different.

Check https://github.com/ZsoltMolnarrr/SpellPower/tree/1.20.1

Yeah, it works! My bad, was watching wrong version. Thank you a lot, youre god!