Quick answer: Jetragon can only be bred from two Jetragon parents. There is no other species combination that produces it.
Jetragon is Palworld's fastest mount and one of the most sought-after Legendary Pals in the game. Because its breeding power sits so far above every other Pal, no mixed pairing ever averages high enough to reach it โ same-species breeding is the only route.
Step by step
Catch a male and a female Jetragon in the wild (it's a field boss, so you'll need a capable team to bring each one down).
Unlock and build a Breeding Farm at base level 19.
Assign both Jetragon to the farm and keep it stocked with Cake.