Those instructions refer to this button in classic Outlook -

Outlook is online in my screenshot - the button background changes when it is offline. Click on it once and be patient - it can take a few seconds for it to come back online.
How to Work Offline in Outlook
I encounter the same problem (after i unlinked ONE DRIVE, the files in ONE DRIVE is only 2.3G of the max of 5G only). I already pointed the pst file to my PC drive under the related user.
There is no way to toggle to WORKING ONLINE for Outlook.
Diane Poremsky : your instruction is NOT working.
Pls check if Microsoft intentionally phasing out certain versions of OUTLOOK so that the Working Online is IMPOSSIBLE. We are wasting time to try this toggle OFFLINE and ONLINE without success. It is NOT working.
Pls provide solution as soon as possible!!!