Thanks for posting in the forum and apologies for the delay. In some cases, the option to use Instant Bank Transfer may not be offered, I am afraid. It may be that our internal security system only allowed this payment to be sent as an eCheque.
To provide one of the safest online payment services our internal security system reviews every payment before it's approved. Occasionally, Instant Bank Transfer may not be available and you may need to send the payment as an eCheque instead.