upgrading from High Sierra 10.13.6 to 10.14

When I follow the instructions below and go to the Apple store and click on the Featured page, I don't have the possibility to click on Mojave Simply powerful banner because it simply isn't there. I need to be able to upgrade to at least 10.14 to be able to install Microsoft Office. Can anyone help?

You can only upgrade to Mojave via the App Store, launch the App Store and then click on the Featured page, click on the Mojave Simply Powerful banner and you will then be taken to a page where you can download the full installer (4.9GBs) for Mojave which installs version 10.14.1. The Apple Support Downloads page only offers the update to 10.14.1 which you must already have Mojave (10.14) installed, so go to the App Store for the full installer.