1.Go to App Design section, and select Theme Customization.
2.In Theme Customization, change app category to Restaurant, and click on confirm to continue.
3.Now, go to App Pages, and select Commerce menu.
4.Click on Open Table to add the feature in the app.
5.In the Open Table section, you can rename your page and change the image icon as per your needs.
6.Now, you need to provide a valid Open Table URL, which you can easily obtain by following the Tutorial present on the right side of the URL listing.
(Note- You can add multiple Open Table URL by clicking on Add More button.)
7.Finally, click on Save & Finish to update the changes.