Hi Poonam,
If you are getting an "Invalid username or password" error while trying to push changes to the Mendix Git repository, it's possible that the credentials you are using are incorrect or have been revoked.
To resolve this issue, you can try the following steps:
Make sure that you are using the correct username and password for your Mendix account. Double-check to ensure that you have entered them correctly and that they are still valid.
Try resetting your Mendix account password to see if that resolves the issue. You can do this by clicking on the "Forgot your password?" link on the Mendix login page and following the prompts to reset your password.
Check your firewall settings to ensure that they are not blocking access to the Mendix Git repository. Make sure that any necessary ports are open and that traffic is allowed to flow to and from the repository.
If this helps you, please upvote and mark as answered!