credcheck doesn't use its schema

[georg-h]

the extension creates an own schema "credcheck" on create extension but doesn't put its views and functions in it.
What is the purpose of this schema?

postgres=# select version();
version

PostgreSQL 15.10 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-22), 64-bit
(1 row)

postgres=# create extension credcheck;
CREATE EXTENSION
postgres=# \dn
List of schemas
Name | Owner
-----------+-------------------
admin | postgres
credcheck | postgres
public | pg_database_owner
(3 rows)

postgres=# \dt credcheck.*
Did not find any relation named "credcheck.*".

postgres=# \dv credcheck.*
Did not find any relation named "credcheck.*".

postgres=# \df credcheck.*
List of functions
Schema | Name | Result data type | Argument data types | Type
--------+------+------------------+---------------------+------
(0 rows)

postgres=# \dx+ credcheck
Objects in extension "credcheck"
Object description

function pg_banned_role()
function pg_banned_role_reset()
function pg_banned_role_reset(name)
function pg_password_history()
function pg_password_history_reset()
function pg_password_history_reset(name)
function pg_password_history_timestamp(name,timestamp with time zone)
schema credcheck
view pg_banned_role
view pg_password_history
(10 rows)

postgres=# \dx credcheck
List of installed extensions
Name | Version | Schema | Description
-----------+---------+--------+------------------------------------------------------
credcheck | 2.8.0 | public | credcheck - postgresql plain text credential checker
(1 row)

postgres=# drop extension credcheck ;
DROP EXTENSION

postgres=# create schema credcheck;
CREATE SCHEMA

postgres=# create extension credcheck schema credcheck;
ERROR: schema "credcheck" already exists

As there is a schema "credcheck" I've expected to find its views and functions within this schema.

kind regards
Georg