Log into the Lightning network through the opening of the payment channel. This requires a transaction in the blockroom (the one in which transactions are always written). The payment channel allows you to send bitcoins between two parties (this is not a new development). To put it even easier, imagine that you use Yandex.Money or Paypal. You can send money to another account within the system quickly and without commissions. The limit is only how much money you have in your account. To enter or enter the payment service, you also need to make a banking transaction (from your card or ATM enter money to your account). Similarly, for Lightning - to open or close the payment channel, you need to perform a bitcoin transaction.