Issuer URL

Issuer is https://api.mobilepay.dk/merchant-authentication-openidconnect

There is a possibilty that there are issues with getting the url to be correct. 

Most OIDC libraries have a possibility to turn of the issuer validation. You can try that. 

Right now, MobilePay cannot change the incorrect Issuer url, because that would entail that MobilePay risks that some integrators validate with their hardcoded values, which results in it failing for them.