pf2e.fyi
From Pathfinder Lost Omens Hellfire Dispatches, which isn't enabled.

Swift Support

FEAT 6
ARCHETYPE
Archetype Nidalese Horselord
Prerequisites Nidalese Horselord Dedication

Nidalese horses are known as some of the fastest across all Golarion, and your mount has trained to ride quickly into battle. When you command your horse to take the Support action, it gains a +5-foot circumstance bonus to its Speed until the start of your next turn.

Effect: Swift Support

Pathfinder Lost Omens Hellfire DispatchesORC