I own base Witcher 3 and Witcher 3 Complete Edition on PS4 but why when I click claim it only show the Witcher 3 base game not Game of the Year?

aren't GOTY and Complete Edition are pretty much the same? Though it didn't say anything about Comlpete Edition in FAQ Claim a free copy of The Witcher 3: Wild Hunt via GOG GALAXY 2.0

or maybe the GOG Galaxy App/Launcher only want me to claim the base game instead the GOTY.

I have not claim my copy yet :)

Sorry for my bad english, but it seems it was solved, just disconnect your Steam account from Gog Galaxy, them reconnect again and VOILA, the banner with your Witcher 3 GOTY will show for you to rescue the game. For me it works.