I checked my Office 365 installation, using Word. The ID number can be found by going to the Word menu and clicking About Microsoft Word. If you can launch Word while booted from High Sierra, you should be able to take a screen shot and print it so that you'll have it when booted into Mojave. BTW, I just updated to the latest version of Office and it went OK. You could do that in High Sierra if you like.


Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365