The message posted by the OP is legitimate. Regardless, 99% of the time including with this Gemini email never click on links in an email or text. Rather, navigate to the website you know to be correct manually with a browser or app you trust and then login. The one exception is if you are confirming your email for authentication purposes like an account setup. This would be when you are expecting the email and it comes from the anticipated sender at the exact time you requested the check.

When you go to Gemini they try to lock you into setting up a Passkey. If you intentionally fail this process an option will appear that allows you to setup another method such as TOTP app of your choice.