Wholesaling, What if I need POF ?? HELP

Hello everyone!

I am starting out and looking to do my first deal but I need some help! When it comes to wholesaling, if the seller asks for proof of funds, what can be a strategy to show them? I was thinking about applying for a hard-money loan and potentially using their pre-approval letter as a way to show POF, and ending up either wholesaling for a quick buck (Probably cutting the lender a percentage of the deal, for only using their letter and not the loan and maybe end up using that strategy multiple times), or end up taking the property in for a rental, and use the BRRRR strategy since the property has a good ROI. I plan on using a hard money or a private money lender in the near future if I can find one that's willing to work with a motivated beginner investor. Any advice is very much appreciated thank you!

By the way, I live in northern Indiana and am looking to start out strong, with an awesome team! I finally pulled the trigger on my real estate investing goals and looking to partner up with anybody interested in investing in the area! Hope to hear from some of you soon. Thanks again.