How to list indexes created for table in postgres

Could you tell me how to check what indexes are created for some table in postgresql ?

The view pg_indexes provides access to useful information about each index in the database, e.g.:

select *
from pg_indexes
where tablename = 'test'

The pg_index system view contains more detailed (internal) parameters, in particular, whether the index is a primary key or whether it is unique. Example:

select 
    c.relnamespace::regnamespace as schema_name,
    c.relname as table_name,
    i.indexrelid::regclass as index_name,
    i.indisprimary as is_pk,
    i.indisunique as is_unique
from pg_index i
join pg_class c on c.oid = i.indrelid
where c.relname = 'test'

See examples in db<>fiddle.