The error message you're encountering while using Git, specifically "fatal: Unable to create '/var/www/html/lms/.git/index.lock': Permission denied," indicates that Git is unable to acquire a lock on the Git index file due to permission issues. This typically happens when Git doesn't have the necessary permissions to modify or access the index file in your Git repository.


To resolve this issue, you can follow these steps:


1. **Check Permissions:** Ensure that the directory containing your Git repository and the ".git" directory have the appropriate permissions. Typically, you should have write access to these directories. You can use the `ls -l` command to check permissions, and the `chmod` command to modify them if necessary. For example:


   ```shell

   chmod -R 755 /var/www/html/lms/.git

   ```


   This command sets read, write, and execute permissions for the owner and read/execute permissions for the group and others.


2. **Check Ownership:** Verify that the files and directories in your repository are owned by the correct user and group. The user running Git should have the necessary permissions. You can use the `chown` command to change ownership if needed. For example:


   ```shell

   chown -R yourusername:yourgroup /var/www/html/lms/.git

   ```

solution -  sudo chown -R wordpresstest:wordpresstest /var/www/html/lms/.git