Designer Repo, There are no staged files

I am trying to commit packages into Repo. For this, I am following the below URL

https://www.netiq.com/documentation/identity-manager-48/designer_admin/data/packmangit.html

I just right-clicked on the cloned repository and click Commit. The Git Staging tab appears

In the Git Staging tab, the package is not showing under Unstaged Changes, then go back to the Git repository tab and right-click on the package file then 'Add to index' after that package is not showing under Git Staging.

When I click on the button 'Commit' or 'Commit and Push', I am getting an error dialog box 'Committing is not possible. There are no staged files.'

Please guide me to resolve this problem.

I am using Designer 4.8.5.