For Windows - follow the instructions on that page.
- Download the manifest.xml file, save it in a new folder.
- Make a network share of that folder.
- Open Excel 2016, open a new blank spreadsheet.
- Click File -> Options -> Trust Center
- Click Trust Center Settings -> Trusted Add-ins Catalogs
- Type in your Network Shared drive/path name into the Catalog URL field and
- Click Add Catalog.
- Check the "Show in menus" checkbox.
- Click OK.
- Restart your Excel. Open any (or new/blank) spreadsheet.
- Click the Insert menu option.
- Click the "My add-ins" button on the ribbon.
- Go to "Shared Folder" tab.
- Select your network shared drive, click Add.
- The new/Beta Excel add-in is showing up on your right-hand pane.