I am trying to do PINT backup and recovery for the standalone database which is not in a cluster.
That is not possible. Its unclear what exactly you mead/did though. Consider sharing actual commands/scripts.
< 2020-06-22 16:34:08.487 CDT >LOG: WAL file is from different database system: WAL file database system identifier is 6840038030519879233, pg_control database system identifier is 6841285371464745049.
You cannot PITR if the WAL doesn’t match the base backup for the cluster you are trying to restore.