viewing connectioninfo used by subscriber on the publication server when inactive

Hello,

(context: logical built-in replication)

On the publication server:

How can you see what is the subscription connection is when this
connection is inactive?
Is there query that can be used?, or is this only possible with extra
monitoring tools (or going through the pg.log files if logged)?
(If so, what would you suggest on debian, preferably available in the
repository of apt.postresql.org or debian.org?)

An example:

# select * from pg_replication_slots;
slot_name | plugin | slot_type | datoid | database | temporary |
active | active_pid | xmin | catalog_xmin | restart_lsn |
confirmed_flush_lsn
-----------+----------+-----------+--------+----------+-----------+--
------+------------+------+--------------+-------------+---------------
------
db2_sub1 | pgoutput | logical | 20751 | db2 | f |
f | | | 171086 | C/C4C4EA08 | C/C4C4EA08
db2_sub2 | pgoutput | logical | 20751 | db2 | f |
t | 9957 | | 171113 | C/C4C90EE0 | C/C4CC0FE0

* so for db2_sub2 there is pid: pg_stat_activity gives me the userinfo
and others,
* but how can you obtain this for the inactive subscription (db2_sub1)?

https://www.postgresql.org/docs/current/logical-replication-monitoring.html
https://www.postgresql.org/docs/current/warm-standby.html#STREAMING-REPLICATION-MONITORING

--
mvg,
Wim
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