sql server - How to use clustering with unique constraints in postgres? -

how can add clustered/nonclustered indexing unique constraints in postgres, equivalent script in sql server below, how can achieve postgres

create table tbl1( col1 int, col2 int, col3 int, constraint uk_tbl1 unique nonclustered  ( col1 asc, col2 asc )) 

any indexing unique constrained columns appreciated.

from docs:

adding unique constraint automatically create unique btree index on column or group of columns used in constraint.