If you want to learn how to decode encrypted samples with DSD-FME (knowing the encryption key), there are a whole range of encrypted samples here:

with a list of commands to use here:
./dsd-fme for linux
or
dsd-fme.exe for windows

with a list of commands to use here:
./dsd-fme for linux
or
dsd-fme.exe for windows
Code:
128-bit key : 373374ABE8E9D13AA90900B9A3101664
256-bit key : 3AF8C96E21BEFDE927EE1D03DF53CFA701516B0642AC7B38643549E2BE79840E
Use DSD-FME Build Version: AW 2025-210-geb76ea2
TYT Enhanced Privacy (AES-128) :
./dsd-fme -Z -i TYT-EP.wav -5 '373374ABE8E9D13A A90900B9A3101664'
TYT Advanced Privacy (PC4) 128 :
./dsd-fme -Z -i PC4-128.wav -! '373374ABE8E9D13A A90900B9A3101664'
TYT Advanced Privacy (PC4) 256 :
./dsd-fme -Z -i PC4-256.wav -! '3AF8C96E21BEFDE9 27EE1D03DF53CFA7 01516B0642AC7B38 643549E2BE79840E'
Retevis Advanced Privacy (RC2) 128 :
./dsd-fme -Z -i RC2-128.wav -@ '373374ABE8E9D13A A90900B9A3101664'
Retevis Advanced Privacy (RC2) 256 :
./dsd-fme -Z -i RC2-256.wav -@ '3AF8C96E21BEFDE9 27EE1D03DF53CFA7 01516B0642AC7B38 643549E2BE79840E'
Baofeng Advanced Privacy PC5-128 :
./dsd-fme -Z -i PC5-128.wav -+ '373374ABE8E9D13A A90900B9A3101664'
Baofeng Advanced Privacy PC5-256 :
./dsd-fme -Z -i PC5-256.wav -+ '3AF8C96E21BEFDE9 27EE1D03DF53CFA7 01516B0642AC7B38 643549E2BE79840E'
Motorola Basic Privacy Key :
./dsd-fme -Z -i MOTO-BP.wav -4 -b 100
RC4-40:
./dsd-fme -Z -i RC4-40.wav -1 373374ABE8
AES-128:
./dsd-fme -Z -i AES-128.wav -H '373374ABE8E9D13A A90900B9A3101664'
AES-256:
./dsd-fme -Z -i AES-256.wav -H '3AF8C96E21BEFDE9 27EE1D03DF53CFA7 01516B0642AC7B38 643549E2BE79840E'