Hello,
I linked my playstation account for cyberpunk with my GOG account but i can't find the goodies because i don't have the game on pc so can't find the bonuses button (i got the collector edition).
Can you help me ?

Hello,

According to someone who uses these third-party integrations, the Extras tab in GOG Galaxy is for GOG games only. So bonus items from other stores can only be accessed in those stores.

On a related note, GOG occasionally puts the Cyberpunk 2077 Goodies Collection and The Witcher Goodies Collection on giveaway. More recently, they bundled the two into CDPR Goodies Collection. If you're interested but don't want to wait, you can try requesting a copy in the community giveaway thread. Bear in mind these two will only show up in your library in a web browser.