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Auth0 SSO OAuth 2.0
Choose Provider Auth0OAuth2 on Jet Admin and after that copy Domain, Client ID, Client Secret from Auth0. You should also set Scope as openid,profile,email,offline_access.
Copy REDIRECT URL from Jet Admin in Application parameters section to Auth0 Allowed Callback URLs and click Save on both - Auth0 and Jet Admin.
SSO button should appear automatically on the login and register pages when visiting Jet Admin from your custom domain.