Fire up Command prompt by right clicking it and selecting ‘Run as Administrator’.

Enter the following command:

Net localgroup Administrators /add "AzureAD\<users office 365 email address>"

Open OneDrive settings (select the white or blue cloud icon in your notification area, and then select Help & Settings > Settings.)

1. In Settings, select Backup > Manage backup.
2. To start backing up a folder, select any folder that doesn’t say Files backed up, and then select Start backup.