Need react native mobile app with integrated Twilio voice call

We want the react native mobile app to integrate Twilio voice calls, and to do the following use cases:
1. callable even when the app receiver is working in the background, killed and locked
2. Missed call shows the correct Vietnamese caller name and makes calls from the call log, receiver side shows correct Vietnamese name
3. show missed calls on the lock screen with the correct Vietnamese caller name
4. A and B in Twilio voice call, B has an incoming phone call, B hold and accepts the new phone call, at this A received a notify

UI: simply in call screen includes: speaker button, end call button, mic button (please refer to the attached file)

Strong requirement points:
- The time from when the receiver accepts the call until the two parties can hear each other is no more than 2 seconds
- Call fail cases must have a signal returned to the participant as a vibration

We need someone who has a lot of experience in implementing integration with Twilio by Reactnative,
when you share the GitHub source code, after successfully building from the source you sent,
and running passed all the test cases we will fully pay.