The idea behind this bot is that you want to take control on who can contact you. Usually you use a public accessible username (@ handles) to be reachable without sharing your telephone number. This also means that strangers could talk to you and annoy you. To prevent that, you could register a bot using https://t.me/BotFather and use this code to have actual contact requests. Also you could then disable the username in telegram.

Configuration

Register a bot using BotFather
Put the API token in your .env file, looking like TOKEN='398iufewj9fierhfefiuosf'
Install python
Start the bot using python TelegramContactProtectionBot.py
Find your bot and /start it in Telegram
Claim your bot by typing /setup

How it works

People can /start and /request to contact you. If the being has no public username it will ask for their telephone number which is deniable though.

Administration

/setup - Write the forename and ID into the config. The forename is used to show to whom this bot belongs.
/block - Block a being. Use the ID to block.
/unblock - Unblock a being. Use the ID to unblock.
/blocklist - Get all IDs who are blocked.
/setname - Set the name which the bot will use.