I paid the property management fee three years ago, and now I have received a letter from my lawyer asking for a receipt (the receipt is missing). If not, is it reasonable to hand it in?

This problem is actually not big. Since it was the property fee three years ago, the property should have been called up three years ago. Why did it drag on until now? Since it is necessary to provide evidence, it should be two-way.

And you are not the owner, and the payment of property fees is continuous for a certain period of time. Check the original stub at a glance, which is required by the property. If the original stub shows that the property fee paid by the owner three years ago is continuous, but it doesn't show that it comes from your home, and you can't provide valid evidence, then the supplement is of course reasonable.