No, it is not mandatory for you to put in the Jetstar middle name while booking with the airline unless you are traveling to Honolulu. For all other countries, you are permitted to enter the details without the mandate option to put in the middle name while finalizing the reservation.
Details on Jetstar Middle Name Policy:
There are certain pointers under the Jetstar name policy which you need to adhere to, if there arises a need to make the changes in the name as per requirement. The details of the same are stated here:
Changes in the middle name is allowed only after you make a payment of the relevant name change fee for the same as outlined by the airline.
Once you make the necessary change in the name, the modification done would apply to all the flights for which the booking has been made... Read More:
https://reservationschart.medium.com/does-jetstar-require-middle-names-no-last-name-fb0c18419d8a