How to create a bot or an account in Viber(Telegram) to send messages?

Question

SMS

There is a customer base (10-20 people).
It is necessary for everyone to personally send a personal message to a viber number, or a telegram, for example, congratulations on a holiday (by name, patronymic, the text is also personal). As I understand it, it will definitely not be a bot, but roughly speaking, an account from which messages can be sent to the customer base. Something like a business account in viber. Tell me how you can implement the idea?

Answer 1

via telegram API - a client, NOT a bot