Answer for myself in future: on Fedora just do nothing! Simplly try to pull git repository with this key. Nice gui will popup and ask you whether to store it in keyring. Now you can use this key automatically after login.

Answering as a future note for myself: on Fedora do nothing! Simply pull git repository with this key. Then gui will popup and ask you whether to store it in keyring. Now you can use this key automatically after login.