How to write a request body (POST) to send a group chat message (telegram)?

Question

Telegram

Good afternoon friends.
Tell me, please, here is the request body, in which the bot sends test messages taken from the variables (marka, model,, year, run) to the group chat. (see below)
But the problem is that I can’t figure out how to write in the request body so that the received picture (s) (for example, let’s call the variable {{picture1}}) is also taken from a personal chat and sent, again, to a group one. Can you give an example of how the continuation of the code will look like? There is simply no experience in writing codes at all. That's why I decided to contact you. I would be very grateful. Thank you.
{
"chat_id":"-1001490780534",
"chat_type":"supergroup",
"chat_tittle":"Cars",
"text": "