How to populate Invoice Description in AP when a refund is initiated from AR

Hi Team,

I am doing a refund from AR but the description is blank when the refund is generated and when it is pushed to Payables the Invoice Description is NULL, how to populate the description when a refund is initiated, I am using API as follows:

  AR_CM_APPLICATION_PUB.ACTIVITY_APPLICATION(

   P_API_VERSION => 1.0,

   P_INIT_MSG_LIST => FND_API.G_TRUE,

   P_COMMIT => FND_API.G_FALSE,

   P_VALIDATION_LEVEL => FND_API.G_VALID_LEVEL_FULL,

   p_customer_trx_id => i.customer_trx_id,

   p_amount_applied => -(i.arhh_tot_amt),

   p_applied_payment_schedule_id => -8,