Prefill registration form with URL parameters

How can I prefill registration form with URL parameters ?
For instance, how can I prefill the “firstname” of the form, if I got the URL as bellow :

https://test.zoom.us/webinar/register/abc?first_name=Clara

Hey @treynaud,

Thank you for reaching out to the Zoom Developer Forum. Currently, we don’t support this functionality with the webinar registration form. Instead, you can create your own registration form that you can prefil and use the Add a Webinar Registrant API.

Let me know if that helps.

Thanks,
Max