How to unblock a third party application

Then you would need to contact Google to unblock it. This has nothing to do with your Apple TV or Apple. This is a Google thing. Log in to your account at Google's website and unblock it from there.

Link-> https://support.google.com/accounts/thread/111344249/this-app-is-blocked-this-app-tried-to-access-sensitive-info-in-your-google-account?hl=en

Not sure why they would do that, when its google that has blocked the app, not Apple.

You may need to generate an App specific passcode from your Google account to use with this App from your Apple device. This is all done from your Google account however.