React Native App - Visitor Verification Functionality

Hello, I am developing a React Native Mobile application for IOS and Android Platforms. It is similar to Mygate App which is available in Google Play store. It is used in the Apartments for Visitor management. Few functionality already developed. I need help ONLY in developing a Visitor Verification functionality. Please note for this functionality will have 2 parts, one will sit at Master App and the other will be at resident app. So this is basically Master App sending a message in form of Pop-up and ringtone to Resident App and then Resident App sending reply back to Master App in the same session. Flow I am explaining here, will discuss in detail with selected freelancers: 1. A visitor comes to Apartment gate and request Security for entry 2. Security guard, using the Master mobile App enters visitor info: name, business name, mobile, pic, flat to visit, purpose 3. Guard searches resident using flat no. and request for visitor entry. And waits for reply 4. A Pop up appears on resident mobile with ringtone and all info captured by guard. 5. Pop up has 2 buttons 'Approve' , 'Reject' 6. Resident presses either approve or reject. Please say 'abra ka Dabra' in the beginning of your bid otherwise I will reject. 7. The selected option is displayed on the Master App 8. If resident does not reply due to any reason then security guard uses second option in the Master App to call resident 9. The call reaches to resident as auto voice call. 10. Resident keys in a number to allow or reject. I think 3 screens will be required to accomplish this. I can provide the hand drawn design. I believe we can use Google Firebase for this, but I am open to suggestions. You have to discuss with me your approach and regarding any library / package or third party paid service if you plan to use. Please bid if you have good experience in building Mobile Apps using React Native. You should be able to showcase your React Native work and should be open for discussion. There are other functionalities also which we can discuss after successfully finishing this work. No Advance. First milestone I will create only after seeing some progress in the Project. The Code should be properly commented and tested. I will also need your help in integrating the function in my Apps. Happy biding!