I am looking at building some integration with our own Event Registration system and I want to copy what GoToWebinar have done, does anyone know how I can add a field like this when editing a form on a Landing Page?
GoToWebinar has a native integration with HubSpot using non-public endpoints, so it won't be possible to create a field like that in the landing page editor.
That said, you can make custom property groups like that with the Timeline API. The Timeline API also allows you create events on contact timelines. You can dictate when and how these events trigger.
For example, if you have a custom registration form on your website, you could tie a special registration event to that form submission. The event would not only appear on the contact's timeline, but you could also set some of your custom property values.
GoToWebinar has a native integration with HubSpot using non-public endpoints, so it won't be possible to create a field like that in the landing page editor.
That said, you can make custom property groups like that with the Timeline API. The Timeline API also allows you create events on contact timelines. You can dictate when and how these events trigger.
For example, if you have a custom registration form on your website, you could tie a special registration event to that form submission. The event would not only appear on the contact's timeline, but you could also set some of your custom property values.