PSQL pass parameter(passwd) to the script

Question

I am struggling to pass parameter(password) from command line into the script.

I have tested many options, but still it's not working. Should I use some dynamic option here?

\set is not working, declaring it before DO statement also do not work. I am out of ideas, any hint may help! thanks

DO $$
DECLARE
    my_password text := **'this need to be passed from CLI';** <--
BEGIN
    IF NOT EXISTS (SELECT FROM pg_roles WHERE rolname = 'username') THEN
        EXECUTE 'CREATE ROLE username LOGIN PASSWORD ' || quote_literal(my_password);
        RAISE NOTICE 'Role created successfully.';
    ELSE
        RAISE NOTICE 'Role already exists.';
    END IF;
END $$;

everything from documentation, google

Found a solution ->

set myvars.pass TO :'passwordfromcli';
DO $$
BEGIN
    IF NOT EXISTS (SELECT FROM pg_roles WHERE rolname = 'username') THEN
        EXECUTE 'CREATE ROLE username LOGIN PASSWORD ' || quote_literal(current_setting('myvars.pass'));
        RAISE NOTICE 'Role created successfully.';
        raise notice '%', current_setting('myvars.pass'); 
    ELSE
        RAISE NOTICE 'Role already exists.';
        raise notice '%', current_setting('myvars.pass'); 
    END IF;
END $$;