Before you start development, the bot must be registered and get its unique id, which is simultaneously a token. For this purpose in Telegram there is a special bot - @BotFather.
We write him /start and get a list of all his commands. The first and main - /newbot - send it to him and the bot asks us to come up with a name for our new bot. The only restriction for the name - it should have "bot" included at the end. If successful, BotFather returns the bot's token.
After that, we enter this token into the application. Specify the pages and bot menu items.