Oisín's Oath lineage support gem for spells

Oisín's Oath description: Mana Leech from Supported Skills recovers based on Elemental Damage Types instead of Physical Damage
On poe2db this gem supports Spells. The question is, is there any spell that can leech mana from physical damage? As far as I know in POE2 mana leech only works for attacks but spells are not attacks? Has anyone tried leeching mana from spells by this gem and does it work?

It also works for attacks. I don't know if any spells have the effect, but I use the gem on my monk. It is socketed in Charged Staff, and therefore works om all attacks affected by it.

Hope it helps :)

Thanks I know it works for attacks. Just want to know how it works for spells. If not then it should a bug to be able to socketed in for spells