SQL & PL/SQL

I want to debug an API procedure named vcar_customers_api.import_customer from SQL developer . Can any one of you please let me know what piece of code can serve my purpose?

//my code for API Call without debug is

Declare
v_cust.cust_name := 'Sunil';
v_cust.cust_number := '1111';
v_cust.profile_class_name := 'VHA OM';
--Ship To Address Details
v_site(0).addr1 := P_ADDRESS1;
v_site(0).addr2 := P_ADDRESS2;
v_site(0).addr3 := P_ADDRESS3;
v_site(0).addr4 := P_ADDRESS4;
v_site(0).city := P_CITY;
v_site(0).state := P_STATE;
v_site(0).postal_code := P_POSTAL_CODE;
v_site(0).country := P_COUNTRY;
v_site(0).site_use_code := 'SHIP_TO';
v_site(0).primary_flag := 'Y';
v_site(0).site_use_status := 'A';

Begin
API Call# vcar_customers_api.import_customer(v_cust, v_site);
End;



I am looking forward to receiving your replies. Thanks.

-Sunil