postgresql.conf
    show config_file
    select setting from pg_settings where name='config-file';
    pg_ctl reload
    select pg_reload_conf();

http://pgconfigurator.cybertec.at/
https://edu.postgrespro.ru/dba1-13/dba1_03_tools_configuration.html
    select ... from pg_file_settings ...
    ... from pg_settings ...

postgresql.auto.conf
    alter system set/reset <par> to <val>;

select pg_settings from pg_show_all_settings ...
!!!
show config_file;