Yes, you are NOT allowed to advertise that on Chaturbate, this applies to any webcam/video messenger service.

This rule is shown in the Chat window of every single broadcast you do on the site:

Broadcaster Rules: Tokens are the only form of payment allowed. You may promote your personal website as long as it does not offer video chat. Do not provide your Skype or Yahoo Messenger to anyone, and do not ask users to chat with you elsewhere.