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The REST API URL is obtained from the status page as described in Tenant status (the URL will be of this format https://servername.superoffice.com/Cust12345/api/v1/)
The Client ID is obtained as described in What is my client ID?
The Client Secret is obtained as described in Create a new client secret
The username and password of the SuperOffice user
The redirect URL (https://www.ayfie.com/openid/callback)