Prefilling Custom Fields via the Zoom meeting URL

Hello,

I would like to know if someone can provide insight on how to prefill custom fields via the Zoom meeting URL.

We are forwarding a Webinar Zoom invitation in which one of the custom questions: I was encouraged to register by?

When Inspecting the web page I found that the id="question_Iwasencouragedtoregisterby?"

The idea is to prefill this field with the name of the sales rep forwarding the Webex webinar invitation.

Thank you.