How to make a gmail email adress work when "on the road", with the Mail Program?

My email from gmail only downloads and I may send emails from home. When I take my Mac on the road and uses friends internet connection it stops working.
I get a warning email from gmail something like that an "unverfied log on attempt was blocked".....

So how to make it work "on the road" / while travelling?

Do you have 2FA enabled?

I am not sure if 2FA is enabled.

Sign out of GMail. Connect to a different Internet connection (friends or on the road), reconnect to GMail. What is the outcome?