There are times you might have to find the PSK in order to share it with a 3rd party vendor or you just need it for your own team. There’s an easy way to find it.
This was performed on an ASA that’s running 8.4(1) code.
kc-fw01# more system:running-config | i ipsec-attributes|pre-shared-key tunnel-group 68.1.2.3 ipsec-attributes ikev1 pre-shared-key Th1s1smyK3y
You can also look at your TFTP backups if you are doing that. They are sent in clear text.