Question about PetSafe Petporte Smart Flap

Good evening Mr Haegloev, we have had this brand of cat flap for decades (our cat passed away at the end of the year). We were even able to sell the flap on.
But now to your question: It has never happened to us personally, one assumption is the battery. Is one inserted or is it still functional? The information on this can be found in the operating instructions from page 115 onwards. Unexpectedly, your entry brought us back to the days of Solbad Sigeriswil, where our daughter Melanie did her apprenticeship. She now works at the Ochsen Münsingen. We wish you a good start to the week. Kind regards H. Schmid