Is WoW Companion App not showing Shadowlands? Your app may not be updated for the latest expansion, or Blizzard's servers may be having some issues. Here's how to troubleshoot Shadowlands on the WoW Companion App.
If you want to use the WoW Companion App, you first need to select the expansion from the menu at the top of the screen. If Shadowlands isn't showing up, you'll have to update your app. That's not the whole story, as the app seems to be extraordinarily buggy right now.
WoW Companion App Not Showing Shadowlands: How to Fix
Some players have reported that the app wanted to be updated, but there were no updates to be downloaded. If this is the case, you may have to uninstall the Companion App and re-download it.
If re-installing doesn't fix it for you, then you'll have to just wait for Blizzard to fix it. Avoid using the app for now if you can, as some players have reported quests getting stuck waiting for rewards.
You might get some success using the app in its current state by switching servers from North America to Europe.