How to organize mailing via viber (viber)?

Question

API

How to send messages with pictures in viber (viber)?
Number of contacts: min 1 - max 100 - 300 (all contacts are more or less familiar, and not from a database downloaded from the Internet).
Frequency: 1 time per month.
Message size: ~150 characters of text + 1-3 pictures.
Contact types: simple contact, various groups.
The device from which the mailing is supposed to be performed: android or windows.
The logic of the application for mailing:

1. Required functionality:
   1. create a mailing list;
      
   2. select contacts for mailing;
      
   3. launch a mailing list;
      
   4. receive confirmation of sending for each addressee;
      
   5. receive a read confirmation for each addressee;
      
   
   
2. Functionality if possible:
   1. chat with a contact in the application (question - answer);
      
   2. voice communication with the addressee through the application (i.e. if the subscriber calls, then in order to answer it was possible through the application);
      
   
   

I started to try to figure it out myself, but I'm starting to get "bogged down" in the information.
Questions.
1. Maybe there are ready-made solutions with this logic or partially the logic described above?
Preferably in one of the following languages:

• JavaScript
  
• Python
  
• PHP
  
• Java
  
• C#
  

2. What is a short plan of action for creating an application with the above described logic?
I would be grateful for a minimal answer with the structure of the action plan and (or) links relevant at the moment for study.