How do I provide my participant ID after an RC meeting has started when I was not provided with an ID prior to dialing in?

I dial in to RC meetings from my desk phone and quite often I dial in prior to when the RC meeting has started. From the email invite, I have the RC dial in # and the RC meeting ID, but I do not have a participant ID. Thus, when prompted for my participant ID I simply hit the # key. When the RC meeting starts (screenshare/video) I am represented in the app as both a RC participant and an unknown caller. At this point, how can I provide my participant ID via my desk phone to merge my duplicate "logins"?