Generate SSH keys on your server so that you can pull from your repository without using passwords.

gitlab_keys.md

cd ~/.ssh
ssh-keygen -t rsa

enter gitlab_rsa leave password empty

cat ~/.ssh/gitlab_rsa.pub

copy, and paste it in gitlab repo settings > deployment keys,

next, need to add gitlab as a source

nano ~/.ssh/config

Host gitlab.com
 IdentityFile ~/.ssh/gitlab_rsa

git remote add origin [email protected]:<repo owner>/<repo name>.git