$ datapatch -prereq
SQL Patching tool version 19.13.0.0.0 Production on Thu Dec 23 12:47:14 2021
Copyright (c) 2012, 2021, Oracle. All rights reserved.

Log file for this invocation: /u01/app/oracle/cfgtoollogs/sqlpatch/sqlpatch_22422_2021_12_23_12_47_14/sqlpatch_invocation.log

Connecting to database...OK
Gathering database info...Error: prereq checks failed!
catconInit failed with 1

Please refer to MOS Note 1609718.1 and/or the invocation log
/u01/app/oracle/cfgtoollogs/sqlpatch/sqlpatch_22422_2021_12_23_12_47_14/sqlpatch_invocation.log
for information on how to resolve the above errors.

SQL Patching tool complete on Thu Dec 23 12:47:14 2021