To expose the add-in to your ribbon bar, do the following:
New Outlook or Web users
Step 1: Select an email and click on the 3 dots > Customize actions.
Step 2: Mark ExtendSync then hit Save.
Step 3: Reload Outlook.
Classic Outlook users
Step 1: Go to File > Options.
Step 2: Select Customize Ribbon then on the Main Tabs, tick the Add-Ins box.
Step 3: Save the changes and reload Outlook.
