Viber. Send a web message to a public account from the administrator?

Question

Viber

Tell me,
How can I send a message to a public account through a browser so that all subscribers can read it? A public channel has been created, there is a token. I'm guessing it should be sent like this:

https://chatapi.viber.com/pa/send_message?auth_token=xxxxxxxxxxxxxx?receiver=11111111?text=test_message

how to specify in the browser to receive a message in a public chat? As I understand it, it should be similar to the Telegram bot, where you can send a message in this way:

https://api.telegram.org/botXXXX/sendMessage?chat_id=12345678&text=test