How do you get the Hydra jet in GTA 5 Online?

I'm curious, how exactly do you acquire the coveted Hydra jet in GTA 5 Online? I've heard it's a highly sought-after vehicle and I'm eager to add it to my collection. Is there a specific mission or set of challenges I need to complete? Or perhaps it's available for purchase through the in-game store? Any insights you can provide would be greatly appreciated.