This concept of this soldier is on my world building, that there was a... Erathon's Korea

somekind of golden cotton sortoff idk and the red feather on the top of the hat, I was wish to put some peacock feather but I'm lazy to make that🥲

For its uniform, it may be inspired mostly by the Napoleonic era style or Franco-Prussian Era style uniform, and the gun itself is a single-round bolt-action rifle, perhaps it's similar to the Chassepot and Berdan rifle then...

maybe an Napoleonic era and Franco-Prussian war era, with the gun may similar to chassepot or berdan rifle, you noticed the traditional hat "Gat" but this one is leathered not made in horsehair or strips of bamboo