pf2e.fyi
From Pathfinder Battlecry!, which isn't enabled.

Mounting Leap

FEAT 4
Activity 1 action
Archetype Cavalier
Prerequisites Cavalier Dedication; trained in Athletics

Requirements You're within 10 feet of a creature that is at least one size larger than you and is willing to be your mount.

You jump atop your mount from afar, landing comfortably astride it. Leap toward the creature and Mount it.

Pathfinder Battlecry!ORC