Re: We are unable to find the site address. Please try selecting a site address from the dropdown.
I figured it out (after sleeping on it) - will share how I solved it
The site I am trying to access is a subsite of a working known site that Flow already knows about and that parent appears in the list of dropdowns when you add a sharepoint action in flow
I created an action and used one of the known links that works when you pick a site in sharepoint (the parent site)
I then used the Peek Code in the 3 dots associated with that action to see the url
I copied that url to my notepad
I then paste that url from peek code into a Custom option for the site address in a new action and it worked
Then I went to my site and copied the url I am trying to access (the subsite) with the flow and compared it to the working url I got from the Peek Code
I noticed the URL from the browser of the subsite had extra characters in it that were not in the known parent site that I had retrieved in the peek code
I modified the subsite url so it looked exactly like the parent site then added the "/" and subsite name
Then the custom option worked and I could see all the lists in that subsite
So my advice if you hit this issue is put in a working known site address into the site address in a SharePoint action and use Peek Code to see how the URL is formatted and make sure the subsite uses the same url pattern regardless of what you see in the browser
Hope this helps someone else - I was pulling my hair out!
