Raspberry pi 4 video-doorbell

I have install Asterisk (with freepbx), for gui to a Raspberry pi 4.

I need a DEVELOPER TO WRITE a succesfull CODE and configurate the system to:

Make a AUTO-VIDEOCALL from extention ''0'' to extention ''1'' or ''2'' or BOTH at the same time.
The exctention ''1'' or ''2'' are log in to androip application, called ''PortSin'''or another app called ''Linphone''.
Extention ''0'' is already loged into Raspberry with the programm ''Linphone''.
When i press a button connected to GPIO 21 i want the audiocall to be started for 9 seconds.
If the call is anwsered I also need to OPEN the DOOR by pushing number ''9'' at the android app.


I have already programm ALL of the above.
But i can only succeed to make auto AUDIO-call ,using NodeRed.
The system is able to make Video call by manual, using a USB WEB CAMERA
I need a code to make it AUTOMATICALLY.

SO I NEED SOME ONE THAT KNOW WHAT TO DO FOR auto-VIDEOCALLING.

The freelancer also must have:
RASPBERRY PI 4
USB WEB CAMERA
ANDROID PHONE

Ideal Skills and Experience:

- Experience with Raspberry Pi4 and Asterisk
- Knowledge of VIDEO streaming
- Proficiency in programming languages such as Python or C++
- Understanding of hardware specifications and integration

If you have the necessary skills and experience, and you are interested in developing a video-doorbell script with live streaming, motion detection, and two-way audio communication, please submit your proposal.

I have already found people that do not know what to do, to a simillar project.
PLEASE ANWSER ONLY IF YOU HAVE THE SKILLS...