Try this on for size:
CREATE TABLE #TEST1 (
    TheDate date,
    itemid int,
    amount int
);
INSERT INTO #TEST1 (TheDate, itemid, amount)
    VALUES    ('03/01/2019', 1, 45),
            ('03/01/2019', 2, 46);

CREATE...

You can try the below query.   It wasn't tested precisely because you provided no sample data to work with:
WITH CTE AS (

    SELECT
        A.EMPLID
    ,    B.FIRST_NAME
    ,    B.LAST_NAME
    ,    A.BANK_CD
    ,    A.ACCOUNT_NUM

Have you given thought to what you just tried to do with a conversion to Integer?   You tried to use a string to hold what should probably be a NULL...

Your GROUP BY includes product, and your picture shows two different values for product for destination BJS.   That would cause your problem.

I'm guessing that given that your data makes no sense, no one is interested in helping you further propagate the nonsense.   Take a close look at your first three rows. ...

Wrapping your T-SQL code in a stored procedure is a matter of syntax, (look up CREATE PROCEDURE) and the usual benefits are those associated with encapsulation as a general principle. ...