Hi JAB65avoca
welcome to the Apple (user-to-user) Community!
Re: Repeatedly request signing google but no where to enter
Wondering if the password you mentioned is for eMail ?
Eg: You may read your GMail in Apple's Mail app, or you may use Google's GMail App for iPhone ?.
You may need to log-in to your GMail account on Google's website, eg: using a web-browser (eg: Safari) or using the GMail iPhone app. Seems Google requires a log-in from time to time ... eg: making sure your account is only accessed by you.
(If needed: See this non-Apple article explaining how to log-in) https://www.wikihow.com/Log-In-to-Gmail )
or
if it wouldn't be a GMail account), perhaps you need to log-in to Google itself online. (if you use Photos, or Drive.)
Try: https://accounts.google.com › InteractiveLogin?nojavascript=1
All the best :-)