Send the following on WhatsApp
Continue to ChatOneDrive for Business - Important Update - Users may need to take action to access OneDrive for Business from Office.com - specially for the users whose UPNs are changed recently in between September 18, 2021 and October 2, 2021 - need to take action by 14 Oct 2021 https://knowledge-junction.in/2021/10/08/onedrive-for-business-important-update-users-may-need-to-take-action-to-access-onedrive-for-business-from-office-com-specially-for-the-users-whose-upns-are-changed-recently-in-between-september/