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The widget javascript snippet can be placed on any site that allows execution of javascript code. For environments that do not support javascript, we have added an iframe snippet to still allow you to load the widget. Of course, browser support is limited to most modern browsers such as Chrome, Firefox and the newest version of Microsoft Edge (chromium)
Where can I place a custom fields such as a phone number field for reservationsthe reservation form?
You can create a custom field on the Reservation Contact object and place this in the Field Set - External Client Fields. You can build automation to copy this field value to the object you want this data on.
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