I want to manage my account with the bot, I want from bot to read messages from my account and reply instead of me without shows that bot is replying, what is the API for authentication to account and get information from the account?
There is a concept of Userbot among telegram users which is basically using a MTProto library to use your own account like a bot .
You can check Telegram-Paperplane which uses Telethon MTProto Library , (Referred this as just an Idea for what you want to do , Check the PMPERMIT feature which might be little bit similar to your goal) ..
Unfortunately it is not written in C# , You need to find MTProto library for C# make something like this to achieve your target .