Insurers want to see after total damage purchase contract

Good evening, I caused an accident due to my own fault. My vehicle suffered an economic total damage, which is why I am trying to regulate the damage to my vehicle with the full insurance. The vehicle was then examined as usual by an expert. As a result, the insurance demanded account details for the payment of the damage, which I had given by phone. 2 hours after the phone call, I get an email that “to the w now the question arises to me what exactly is to be examined there. What do you need the purchase contract for? And could the insurance deny the settlement due to a missing purchase contract? Mfg