Buying on a wrap

I’m looking at a mobile home park with 52 spaces, lots of upside, no park owned homes. It fits all my criteria. However, the seller still has an underlying loan. She is willing to finance the deal as well, but my down payment wouldn’t be enough to pay off the underlying loan.

I’d like to know, if this deal comes together, how to possibly buy this on a wrap or maybe there’s another option I’m not thinking of. I really don’t want to try and get a new loan.

I’ve heard that it is common for a lender to call the loan due with commercial loans. How important would it be to get the lender’s approval to wrap the loan? Is this needed?

Thanks for any input!