Initialize OAuth flow for an integration
google-analyticsnotionslackzohogmailcom - US data centereu - EU data centerin - India data centercom.cn - China data centercom.au - Australia data centerZohoCRM.modules.ALLZohoBooks.fullaccess.ALLZohoProjects.projects.ALLpassthroughRedirectUri should be a URL in your application that can handle the OAuth callbackexternalUserIdentifier to associate the integration with the correct user after the callback