Live e-learning plugin

Hello..

I would like to ask if there is any plugin (or any other way), to create an online course.

I don’t need to pre-create the course (write a text, or show a video), but users register (maybe pay) and be me the teacher in real time.

I would speak to them, they will listen me, they will show my desktop and in a chat they will ask questions.

How can I perform that??

Thank you!!