Create a bot for auto-greeting!

Looking for a specialist who can develop a Telegram bot with the following functionality:

The bot must:

• work correctly with both groups and closed Telegram channels;

• be added to a closed channel and automatically:

  • send a welcome message to the user,

  • send a captcha when applying to join.

👉 The captcha is a message from the bot at the moment of application, similar to the greeting, but with text buttons.
When the button is pressed, the user automatically sends a message to the bot, the interaction is recorded, and after that, the bot gains the right to message the user not only in the first 5 minutes, but to use it for further messages and broadcasts.

Additionally:

• the ability to make broadcasts;

• the bot must be multi-user (so that other clients can use it);

• availability of free plans (with limitations and displaying message chains set by the administrator);

• paid plans with payment:

  • by bank card

  • by cryptocurrency.

🔎 Analogues and benchmarks

Services that can be referenced for logic and functionality:

• Tgreet

• ChaBooster

• NeService_bot

A more detailed description of a similar solution can be found here:
👉 https://instruction.nebot.space/