When the Well-Known URL is pasted into a browser, it returns a JSON listing of the OpenID/OAuth endpoints, supported scopes and claims, public keys used to sign the tokens, and other details.
Clients can use this information to construct a request to the OpenID server. The example below is the response returned from the ADFS server for the Well-Known URL.
The response includes the two URLs required by the PTT Pro server to complete the OAuth configuration: the Access URL and the Token URL. Examine the Well-Known response to find the Authorization Endpoint and the Token Endpoint.