Gramps Web Sync error connecting to server

Gramps 5.1.6
Gramps Web API 1.5.1
Gramps Web Frontend 24.1.2
locale: en
multi-tree: false
task queue: true

Gramps web sync says “error connecting to server”.

With http logs show:
nginx-proxy | nginx.1 | - - [09/Feb/2024:21:20:29 -0500] “POST /token/ HTTP/1.1” 503 190 “-” “Python-urllib/3.6” “-”
nginx-proxy | nginx.1 | - - [09/Feb/2024:21:20:29 -0500] “POST /api/token/ HTTP/1.1” 503 190 “-” “Python-urllib/3.6” “-”

With https, the same error in Windows, but no entry at all in the grampsweb logs.

Ah, once again RTFM comes to the rescue. I was attempting, as had been successful in testing, to access grampsweb via IP address, locally.

I mean, if it worked once . . .

When I reviewed the docs, it gave as the example, the URL of the site.

And, remarkably enough, that worked fine, so, problem solved.