Requests to an API endpoint denied due to Testcafe prepending request URLs - solutions?

When Testcafe runs against our local site, every request it makes during the test steps are prepended with something like http://192.168.1.182:59304/http://localhost:3000 (port number varies per run).

For the most part this works, but our web application makes calls to certain APIs during a user journey, and within TestCafe they might look like: http://192.168.1.182:59304/http://www.example.com/api/v2/customers/1 which come back with a 401 and response body of 'unauthorized'. Some API calls are fine, however.

I guess my question is:

• Are there any way to get around this from my side, such as rewrite certain requests, or do I need to contact the API provider - and if so, what would they be potentially looking to do to allow these requests to go ahead?