It looks like a IP geolocaion API. However, it has missing authentication under the readme.
Re:Ask HN: What is this user doing?
by justtologin on Saturday December 18, 2021 @07:44PM
(#29610264)
No I wasnt clear, I used the api at ipinfo.io to get the information about the ip address the parent had posted. That info pertains to the "problem" ip he is encountering, its not generated by some service at that address
Edit: unsubstantiated source [0] says that domain relates to Google app engine, so could be the person is working on a project that includes some form submission capability and somehow is using your site for testing
https://superuser.com/questions/892437/what-do-you-do-if-you...