How to find end user given database session info?

FSCM 9.2, tools 8.59.16; Oracle database 19c

In the PeopleSoft database, username of v$session is always the generic 'SYSADM'. Columns module, action, and client_info of this view have more information but none tells us what the end user is. Note

E-SEC/AS: How to Retrieve Information on Users Currently Logged In/On (Doc ID 614861.1)

is closest to what I want, e.g, running the SQL in the note

SQL> select nvl(b.oprdefndesc,'Blank'), a.CLIENT_INFO
 2 ,a.OSUSER, a.machine, a.PROGRAM
 3 from v$session a, psoprdefn b
 4 where
 5 a.USERNAME is not null
 6 and substr(a.client_info, 1, 7) = substr(b.oprid,1,7)
 7 /

NVL(B.OPRDEFNDESC,'BLANK')    CLIENT_INFO                        OSUSER              MACHINE                                 PROGRAM
------------------------------ ----------------------------------- -------------------- ---------------------------------------- ------------------------------------------------
MDA-System User Profile       PSMAPPS,psoft,appserver01,,PSAESRV, psoft               appserver01                             PSAESRV@appserver01 (TNS V1-V3)
...