BRRRR strategy real estate

[Samuel Chua]

Good evening, I hope you have a good day. I have a question to ask. Does the BRRRR method work for flipping only? Also, why must I rent the property out before I sell the property? Why cant it just be "get a loan from a private lender, flip the house and sell it out" or "get a loan from a private lender, flip the house, get an official loan from the bank (Refinance) and sell it"? Thanks!