Need some help to access client’s WP admin portal

I am working with a client who hosts a WordPress website on GoDaddy. This client has worked with previous marketing companies and web developers, but has recently lost access to his WP-admin portal. His website is live with no issues, just unable to access the wp-admin because we don’t know password. When we press the reset password, an reset link is sent to his email. After clicking on the link, we get an error: “Hmmm… Can’t reach this page. Check if there is a typo in email. {domainname} .com with error code: DNS_PROBE_FINISHED_NXDOMAIN

He used to be able to access the WP admin portal with no issues. It was only after he installed a new plugin (Podium – for a webchat feature), that he can no no longer access the admin portal.

Any assistance would be appreciated including troubleshooting steps needed to properly diagnose what’s happening. I’m not a WordPress developer just trying to help out a client regain access. Thank you!

The page I need help with: [log in to see the link]