Webinar Chat Functionality, Lock it to Host and Panelists only

We're disabling the Q&A functionality and instead would like to use the Chat feature for questions however we only want the questions to come to the "Host and Panelists" instead of "Everyone". Is there a way to lock it to only "Host and Panelists"? Right now attendees are able to toggle between the two but we want to disable that.

Thanks!