Please do the following,

1. Update Credentials: Run the following command:

   git config --global credential.helper cache

   Then, try pushing to prompt for credentials.

2. Use Personal Access Token (PAT):If using HTTPS, generate a PAT on GitHub and use it instead of a password.

3. Check SSH Key: If using SSH, ensure your SSH key is added to your GitHub account. Test with:

   ssh -T [email protected]

4. Verify Remote URL: Check your remote URL with:

   git remote -v