Open Account, then Invite friends. Copy your personal link, or share it by WhatsApp or email. Anyone who joins through it starts with a longer free trial of 30 days. Once they have paid for 3 months, you get 3 months of the Business plan free.
The panel shows how many people joined, how many are paying, and the months you earned. Months are added to your account and never paid out in money. If your plan is active when you earn them, they are saved and start automatically when it ends.