How to use money from friends and family?

[Will Eagles]

So i have been watching a lot of the biggerpockets podcast and something keeps coming up. There are a lot of people who are using money from friends and family. How does this work? How do they get paid? How to I make money if I'm paying back a loan to friends and family. For example say I find a rental that I want to purchase. I raise the down payment money from family and buy the property. How do I pay them back but still make money every month? I feel like I'm missing something.