CSOM # APP Only Policy - JackHu88/Comm GitHub Wiki https://social.technet.microsoft.com/wiki/contents/articles/31338.sharepoint-online-using-app-only-policy-to-create-site-collection-in-sharepoint-online.aspx https://stackoverflow.com/questions/46936082/access-denied-accessing-sharepoint-online-site-collection-with-app-permission/47318600#47318600 https://docs.microsoft.com/en-us/sharepoint/dev/sp-add-ins/authorization-code-oauth-flow-for-sharepoint-add-ins