Need java spring boot and angular js developer -- 2

my project is The platform allows students to search for and select a tutor based on their preferred subject, level of expertise, availability, and hourly rate. Tutors create their profiles on my project, outlining their qualifications, teaching experience, and approach to teaching. They also set their own hourly rates, which can vary depending on their level of expertise and the subject they teach. Now i want, after student pay the tutor he can start chat and/or video conference using the api of opentok

API
https://tokbox.com/developer/guides/

Angular js front end
https://www.mediafire.com/file/mfvrs8h7vpaxymx/angular-client_v4.zip/file

Java backend
https://www.mediafire.com/file/ksuce1fimx6qjlk/backs-main+(1).zip/file