When you install the "Book now" button, once your customers click on it, the booking calendar will prompt.
Step 1: install the Global Code
This step is very simple to perform and you can see how to do it here.
Step 2: edit the data-embed attribute
In this step, what you need to do is edit the "data-embed" attribute of the widget code from "box" to "button". This would be an example:
<div class="load-turitop" data-service="P1" data-lang="es" data-embed="button">Reserva ya</div>
The button will look like this: