Wrangling around in the depths of old posts I came across this wonderful thread on enabling google sign on for custom login.
The process works well, with results as you can see from my rough integration.
Until, you attempt to work through the OAuth authentication and find that your login is failing because Wix is routing your site to google, (via an iframe), through a completely different domain than the one you own, namely yoursite.com.filesusr.com.
You can fix it, but only by authenticating filesusr.com as an appropriate origin site, which creates a user experience no one wants. Namely
According to this excellent thread, lots of people seemed to have this problem back in 2018, but I can't find any non-iframe solutions proposed, except for the zomato example which won't work in this case. So, in the hope,filesusr.com workarounds. Then a general question so I don't lose faith - the amount of time I've spent in custom log in and sign up is enormous because 1. I need to route to a specific post log in landing page 2. it's better cosmetics and helpful for data collection. But I really do also need Google log in Worst case I'd take a messy redirect instead. So, honestly Should I persist? How many more rabbit holes are there, or should I just revert back to Wix standard sign up and log in?