A new provider we are using does not supply any userinfo_endpoint and only code for response_types.

Is there anyway to support that use-case?

The only thing I have been able to find is that userinfo_endpoint is RECOMMENDED and not REQUIRED in the discovery definition: https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata

I added an issue to the underlying package as well: nov/openid_connect#82 where the issue is raised.