After adding the provided ISF file to the correct folder in the Volatility3 installation,
you can extract the bash history from the core dump with vol.py -f debian11.core linux.bash.Bash.
This gives:
PID Process CommandTime Command
467 bash 2023-03-05 18:21:23.000000 # 08ffea76-b232-4768-a815-3cc1c467e813
and 08ffea76-b232-4768-a815-3cc1c467e813 is the flag.