The Discovery document URI has the following format:

<OpenID Provider’s issuer value>/.well-known/openid-configuration

The URL must start with https:// according to the OpenID Connect (OIDC) Discovery 1.0 specification. For more information, see https://openid.net/specs/openid-connect-discovery-1_0.html.

For example:

https://www.example.com/.well-known/openid-configuration

<----- OP issuer -----><------ Spec defined path ------>

Tip:
If you are connecting to PingOne DaVinci as an external identity provider, the discovery endpoint is one of the following, depending on whether you have a custom domain:
Custom domain

https://<customDomain>/davinci/.well-known/openid-configuration

Default domain
https://auth.pingone.<region>/<envID>/davinci/.well-known/openid-configuration

For more information, see Domains.