While creating new integration it throws "your certificate is not valid!"

Hi

I have followed the auth-methods (Service account integration) and created the public key certificates and uploaded the public certificate (certificate_pub.crt) as a part of creating the integration. But when I click create integration. It says "your certificate is not valid!"  and provide the url to follow which is the same I used to create these certificates.

Looking to know how I can create a new integration to use Adobe services, like user management apis.

Thanks
Rajat