update supplier silte using API

Dear All,

I'm trying to update a supplier site using the API Mentioned in following link but it doesn't update the data knowing that it gives no error.

https://docs.oracle.com/cd/E18727_01/doc.121/e16533/T553628T553644.htm

Create or replace PROCEDURE  XX_update_supplier (nb in number) IS

    l_vendor_site_rec ap_vendor_pub_pkg.r_vendor_site_rec_type;

    l_return_status VARCHAR2(10);

    l_msg_count NUMBER;

    l_msg_data VARCHAR2(1000);

BEGIN

select sup.vendor_id

INTO l_vendor_site_rec.vendor_id

from ap_suppliers sup

where sup.vendor_name= 'supplier002';

dbms_output.put_line('vendor_id: '||l_vendor_site_rec.vendor_id);