From MetaTrader 5 Help - Open an Account
Live accounts, unlike demo, cannot be opened straight from the platform. They can only be opened by brokerage companies under certain terms and conditions. However, a real account request can be sent to a broker from the trading platform.
This can be done by specifying "New real account" in the account type selection step. Next specify your personal details, like when you open a demo account. A preliminary account is opened then on the broker's server. This account is created with a zero balance; and trading from it is disabled.
Soon after opening the preliminary account, a representative of the brokerage company will contact you to finish the procedure of real account opening. After that the preliminary account is converted to the real one, and you can start trading from it.
An informational email is additionally sent to you via the internal mailing system when a preliminary account is opened.