Using OneDrive to backup Documents

For backing up of normal documents, i am trying to use the backup feature of OneDrive. Right clicking on the OneDrive folder, click on the Backup Tab, then click on 'Manage Backup'. A dialog box appears saying that "it cannot backup my 'Documents' folder due to my .pst file being in the 'Documents' folder. To continue move this file and try again". Yet in Windows 10, i cant seem to be able to add a 'New Folder' to 'This PC' outside of the current default folders(Documents, Downloads, Music, Pictures, Videos) ??

This seems strange? Am i missing something simple here? Where am i supposed to 'move' the .pst file to so OneDrive can backup my 'Documents' folder?

....cheers.

Digital Life said:

It wants you to get the .pst out of that folder just move it anywhere for now no need to create a new folder. If you cant find the file enable show hidden files in file explorer.

If it means anything to you a .pst file is for Outlook the email program if you don't use outlook I would delete it.

Yes i know what a .pst file is. That is a whole different discussion, on backing up my .pst file.
So, lets forget about my question being around the moving my .pst file. In Windows 10, i cant seem to be able to add a 'New Folder' to 'This PC' outside of the current default folders(Documents, Downloads, Music, Pictures, Videos) ?? ...why is that.