How to pass table column values to function

[Andrus]

Hi!

Table source contains integer column. Its values should be passed to 
function for selecting data from other table.

I tried

        CREATE OR REPLACE FUNCTION 
public.TestAddAssetTransactions(dokumnrs int[])
         RETURNS int AS
        $BODY$

        with i1 as (
        INSERT INTO bilkaib (dokumnr)
        select dokumnr  from dok where dokumnr in (select * from 
unnest(dokumnrs))
        returning *
        )

        select count(*) from i1;
        $BODY$ language sql;

        create temp table bilkaib (dokumnr int ) on commit drop;
        create temp table dok (dokumnr serial primary key ) on commit drop;
        create temp table source (dokumnr int ) on commit drop;
        insert into source values (1),(2);

    select TestAddAssetTransactions( (select ARRAY[dokumnr] from 
source)::int[] )


but got error

> ERROR: more than one row returned by a subquery used as an expression

How to pass set of integers to function? Should temp table with fixed 
name used or is there better solution?

Using Postgresql 12+

Andrus.