I want to create a new SSH key with specific permissions or for only one or more repository, to be able to use it securely in a server that has many admins alongside me, so, I don't want anyone with access to the server to be able to access all my private repositories but the only specific repositories.
Notice: I didn't create the specific repositories, but I have access to (someone gave my account access to it).
I don't know if that's even possible in GitHub or not.
I have googled for some answers but the only thing I got is for only my repositories, the repositories I have created not the one that someone gave me an access to. I also tried the new "New fine-grained personal access token" thing and only found out for only my created repositories, and the deployed keys in a repository under "Settings" tab, also for my created repositories only.
So, how can I accomplish this?