Add div into the place where you want to have widget. Open advanced settings for the added div and add j-hostme-widget style

Add two data attributes into the added div:
      1) data-hostme-id="4332"
     2) data-allow-fast-booking="true"

Go to site settings and edit the BODY section adding the following script:
​      <script src='https://tables.hostmeapp.com/widget.js' async></script>