You can also check the corresponding section of implementation of video conference calls in our documentation:
iOS SDK - Video Conference | iOS SDK | QuickBlox
Android SDK - Video Conference | Android SDK | QuickBlox
Please note that conference calls are available as an add-on to your current plan: Chat API & Messaging SDK Pricing | QuickBlox
Feel free to check our official documentation for more information that will help you to integrate QuickBlox services into your applications / projects or contact our Support team by submitting a ticket if you have any other questions.