FN-1226 was a human male who served in the First Order's FN Corps as a stormtrooper in 35 ABY. When Rey arrived on the Star Destroyer Steadfast to rescue Chewbacca, the young Jedi confused FN-1226 and another stormtrooper with a mind trick.
FN-1226 first appeared in the 2019 Star Wars film Star Wars: Episode IX The Rise of Skywalker where he was played by J.D. Dillard, a screenwriter and director which J.J. Abrams had worked with in the past.