Hello Dr Kiljanek, It looks like the api sandbox has a CORs error.
Thank you!

https://endlessmedical.com/sandbox/

Fetch errorFailed to fetch https://api.endlessmedical.com/swagger/v1/swagger.json

Fetch errorPossible cross-origin (CORS) issue? The URL origin (https://api.endlessmedical.com) does not match the page (https://endlessmedical.com). Check the server returns the correct ‘Access-Control-Allow-*’ headers.