Expense Audit Reasons API - "AP_WEB_AUDIT_HOOK" not working

I am using 'AP_WEB_AUDIT_HOOK' to define additional audit rule in iExpense (r12).

But custom audit reason is not populated into expense report headers table due to which the expense report is not selected for audit.

The code used in the hook is as below:

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PROCEDURE audit_expense_report(p_expense_report_id IN NUMBER,

p_audit_reason_code OUT NOCOPY VARCHAR2,

p_audit_report OUT NOCOPY BOOLEAN,

p_override_default_processing OUT NOCOPY BOOLEAN) IS

V_CASH_AMOUNT number;

BEGIN

p_override_default_processing := TRUE;

p_audit_report := FALSE;

p_audit_reason_code := 'CUSTOM';

BEGIN

select sum(submitted_amount)