Unlisted app-ads.txt requirements?

Does unity have limited custom port range? Or http vs https requirements?

I get the “could not find your app-ads.txt” error.

I checked with httpstatus.io and it show success, code 200, content type text/plain.

I tried http with static IP and domain.
http://vi.zenithnetwork.com:6042/app-ads.txt

If it work for 3rd parties such as Google, i would assume it should work for Unity, too?

Looks like this website will return a 304 response, please note the 200 response is the only response code that will work for our crawler, you might need to change the response code to 200.