You will start to receive the notification for a transaction event (TRANSACTION) after creating a webhook endpoint as shown below.
When the event = TRANSACTION, message_type = AUTHORIZATION; then the webhook notification can be received for CASH_WITHDRAWAL, PURCHASE, REFUND, and REVERSAL as per the configured transaction type shown below:
Sample
When the event = TRANSACTION, message_type = API; then the webhook notification can be received for WALLET_CREDIT, WALLET_DEBIT, and WALLET_TRANSFER as per the configured transaction type shown below: