I need to make a customization

I need to present a certain idea I need a way to do the following When the student needs to solve some questions or explain a specific lesson can be written in a dedicated space with the choice of the required specialization and this application is sent In this case, the request is also sent to teachers online via a bell message to be heard only by existing teachers and we prefer to be in the same specialty. The request will be accepted by the teacher if they are able to explain it and are available If more than one teacher accepts the request, the student chooses his or her preferred teacher and an online metting is created The quota price is calculated according to the time it takes After completing the slot , the slot is evaluated by the student The student is counted at a certain price per minute and also the teacher, but at another specific price