Conference Rooms and Zoom Webinars

[RickYO]

Hi, we have conference room systems that are not Zoom-based but will support  Zoom calls by allowing manual entry of the meeting ID and passcode. We recently ran into an issue where we tried to join this room to a Zoom Webinar/registration event but we were unable to do so. We hit a wall after we were prompted to register for the event after it had started. It asked for us to join the meeting by downloading and opening the Zoom client, but this was not an available option on this conference room system. 

Is there a way to invite a user to a Zoom webinar as if it were a regular Zoom meeting? Or somehow allow a single user to bypass the registration all together?