If a person you owe money to has died, and the deceased DID NOT have a will, do you still have to pay back the loan?

i owe money to a person, we have a notarized I.O.U….this person passed away..i have read answers on this site, that you have to still repay the ‘note’ to the executioner of the estate, unless the debt was forgiven….i doubt mine was, but what if there was no will from the deceased? thank you!!