Permission denied (public key) for hosted gitlab

**Topic**
I can't use SSH to contact a git(lab) repository, but are forced to a https url as remote.
In Lazygit i'm unable to fetch or push data, because of authentication problem.
`Permission denied (public key)`

**Your thoughts**
I would expect that at least I'm prompted to enter my passphare for my private key.
That isn't happening, so I assume that this is the reason why it fails.
How does lazygit work with HTTPS git repostories?
Can someone please help me?

Nice to have feaure: It would also be interesting in lazygit if it caches the password or the decrypted private key as long the process runs.