First, make sure you have an access token. If you don’t have a token, click on the user area in the top right corner within GitLab and select “edit profile”. From the left menu, choose “access tokens”. On the screen that appears, create an access token.

Run the following commands to add your local folder to the GitLab repository.

cd existing_folder
git init

git remote add origin 
http://username:access_token@repository_path_for_this_project

git add .
git commit -m "Initial commit"
git push -u origin master