To unlock the Springboard trophy in Far Cry New Dawn, you will first need to progress through the story to a mission in Act 2 so that you are able to purchase the Leap of Faith gold perk for 7 perk points. Once acquired, this will allow you to press X whilst in the air for additional jump height -- basically a double jump.
To survive a 30m fall using only the Leap of Faith perk, you can find a cliff and jump off. If you absolutely want to make sure that you will be falling from a height of more than 30m, upgrade your Expeditions to level 3 at Prosperity and select an Air Drop from the fast travel menu.
Instead of opening your parachute or wingsuit, keep free-falling and then press the X button just before you hit the ground to land safely on the ground and unlock the Springboard trophy.