How to protect your Telegram account from hijacking?

Telegram is not just a messenger. Correspondence, documents, channels, even a wallet - all this is contained in your account. It is important to ensure the security of your account in advance. How to protect your account from hijacking? What is a cloud password and how to set it? How to set a password for the application itself? What to do if you have lost access to your account? How to track if someone has access to your account?