It might because they don't want any random person just setup a property management software to make it look legit and using it to scam people (tenants)

I typically don't comment on other's businesses unless I know from personal experience.

Private money and personal funds.

Then I spoke to a company that does business lines of credit, based on personal FICO scores.

A business line of credit through your LLC protects personal assets, builds business credit, and may allow interest deductions, but it might be harder to secure for a new LLC.

I also use business lines of credit from banks, but for this banks definitely want to see revenue (usually 5-10x the amount of a mine they will give you).It is important to remember though that just because these lines and CCs are not immediately reported on your personal credit report, if you miss payments or default you are personally liable and the debtors will add it to your personal credit report.

What's the lowest credit score you will allow?

I would say credit monitoring

When you tell them they will only get paid when the loan closes, they will disappear.If required, the only money you should ever send to the lender is for a credit check.

She is not in a position to lend a personal loan to me.