No "Annotate" button on "Markup" toolbar in Preview on Mac
Apple's page "Annotate an image in Preview on Mac" claims that an "Annotate" button should appear in the Markup toolbar for Continuity devices (see screenshot):
https://support.apple.com/guide/preview/annotate-an-image-prvw1501/mac
This is not the case for me, either on my iMac or my MacBook Pro. I have tried to find the Annotate button in "Customize Toolbar" but it isn't available (see screenshot).
I'm running MacOS 10.15.6 (19G2021) on both machines.
Continuity/Handoff are working fine, and I see the Annotate button in QuickLook (see screenshot)—but never in Preview.
Is the Apple document wrong, or is there something wrong with my computers?
Thanks in advance!
William
iMac Line (2012 and Later)