The void and refund options are only available for eligible transactions - those that have been approved and have not been voided or refunded previously. For security reasons and your convenience, if a transaction is not eligible, these options will not appear when you select the transaction in the Ingenico Tap to Pay app.
Additionally, you can only void a transaction on the same day it was approved. If you need to refund or void a transaction after the same day, you will need to use the refund option.