This python script forwards AirTag reports to the GPS Tracker Server 'Traccar'. It is based on biemsters Project 'FindMy' and requires the steps mentioned in his repository to work. In addition, you need to create a folder named .keys and copy your keys into it. The script re-reads that folder with every round, so adding keys during runtime is possible.
Further explaination is provided in c't and on heise+ (to be released).