If I have Galarian Zapdos V with "Fighting Instinct" Ability active and an Earthen Seal Stone attached, and my opponent has 3 Pokemon V in play, can Galarian Zapdos V use Earth Sealing Stone's "Star Gravity" attack for free?
Yes, you can
Source: TPCi Rules Team (2022-11-10)

Relevant cards

Note: All applicable cards may not be listed below.
SWSH6_80
SWSH6_80
SWSH12_154
SWSH12_154