As per Facebook requirements, you can only have a booking engine integrated into Facebook if your Facebook page has at least 2,000 fans.
Does your page have 2000 followers? So here is the procedure to connect the Smoobu booking tool with your Facebook page.
Just click on the following link: https://woobox.com/
Create a profile (for free) by clicking on SIGN IN and then proceed with the creation of the app for html following this procedure (see attached photo):
2. Choose "Set tab"
3. You will be redirected to the page where you can deposit your occupation calendar or the Smoobu booking tool.
4. You can find your code from Smoobu under Settings -> Availability calendar
5. Publish the codes from the calendar and / or from the booking tool, then choose Save / Publish
6. Go to your Facebook page and you will see the new tab
7. Do you want to change the order of the cards? Go to the Fanpage settings and go to the "Edit page" menu item.