I setup everything to use SSH key to connect to my Gitlab repository. I tested with
ssh -T firstname.lastname@example.org and it is showing the welcome message. But it is still asking for my username and password when I run the following command.
git pull Username for 'https://gitlab.com':
Notice the https part of the result from the command above. Well, my current repository is still using HTTPS. I have to switch it to use SSH. I ran the following command.
git remote set-url origin email@example.com:USERNAME/PROJECT_NAME.git