Is it possible to automatically send a message to a Telegram channel from a program without manual interaction with the bot?

Question

Java

Good afternoon, there is a task: to automatically post a String object to the telegram channel through a written utility, the launch of which should post the message itself.
I use the TelegramBots library ( https://github.com/rubenlagus/TelegramBots) and the long polling method recommended in its documentation.
The problem is that the written utility starts posting only if you manually write any message to the Bot that administers the channel first via Telegram. Is this a feature of the long polling method, or is the problem most likely in incorrectly written code and can this process be automated?
Thanks for the reply, sorry for the stupid question.