issuer
REQUIRED. The authorization server's issuer identifier, which is a URL that uses the "https" scheme and has no query or fragment components. Authorization server metadata is published at a location that is ".well-known" according to RFC5785
derived from this issuer identifier, as described in Section 3. The issuer identifier is used to prevent authorization server mix-up attacks, as described in "OAuth 2.0 Mix-Up Mitigation" MIX-UP
.