How did they get this Book Online button on Google Maps?

[neel123]

 

[silverlinestudio.eu]

By setting up an account with a Google booking partner.

Here is the list : https://www.google.com/maps/reserve/partners?ihs=3

 

[klharris08]

This dental office has partnered with NexHealth to power their online scheduling. NexHealth has setup an integration with Google and this is what allows for the "Book Online" button to show up in SERPs. If you want the same functionality, partner with a booking provider that has this integration setup with Google. Here's a list of some of the partners, but not all. I don't think Google's updated the list in a while. https://www.google.com/maps/reserve/partners?ihs=3