How to issue borrowers loans as a Fintech company?

Hi guys, I am thinking to start a fintech company which will allow customers to get the loan so that they can pay the merchant, similar like what affirm does. For affirm, they partner with Cross River Bank, Cross River Bank is the creditor to provide the capital. I am wondering for small startup like us, if we cannot get backed by licensed banks, how can we issue loans to our customers? Can we use our own fund to do so, or we need to team up with bank? Thanks!