Can't pull remote branch. LFS Error downloading object

I’d been using LFS for over a year with no issues until this morning. I try to pull a remote branch, and I get this error:

Error downloading object: xx/xx.png (xx): batch request: git@gitlab.com: Permission denied (publickey,keyboard-interactive).: exit status 255

I have no experience with the terminal, I use Fork as a git client. Any help appreciated!

I’ve cloned the repo via HTTP and was able to pull the branch. Not ideal, but it’s a work-around