Both on my local and in upstream environments, the "Review" tab is missing in the Experience Editor (even when I'm signed in as an admin):
However, the Content Editor does show the "Review" tab:
This is a problem because users cannot submit items to be approved when they are working in the Experience Editor.
I'm using Sitecore.NET 9.0.2 (rev. 180604).
How can I enable the "Review" tab in the Experience Editor?