The most dangerous files are the "patcher.exe" or "crack.bat" files you find on torrent sites. Security researchers (like those at Malwarebytes and Kaspersky) have repeatedly flagged these files as Trojan.Poweliks or Generic.Malware.SFB. You might get a free driver, but you will also give a hacker remote access to your PC.
Searching for "license keys" or "cracks" for this specific software carries high risk: alternative a2dp driver license key
Let me be blunt: There is no working, safe, or "free" license key for the current version of this software. The most dangerous files are the "patcher
Any website offering a "key" is either:
The developer has implemented a system where keys are tied to your hardware ID. Even if you get a key, the software checks a cryptographic signature. If it fails, the driver reverts to "Trial Mode" (30 seconds of audio followed by silence). The developer has implemented a system where keys
If you are truly anti-software-cost, install a dual-boot of Ubuntu or Fedora. Linux handles A2DP natively with perfect codec support (including LDAC via PipeWire) and it costs exactly $0. You lose your Windows games, but you gain perfect audio.