How to get rectalinear coordinates on using projected data, instead of geographic coordinates.

Aloha. I have data that is in UTM4N (meters) and when I plot it using

p1 = ggplot(HI_L0_26904) +
geom_sf(aes(fill=NAME)) + coord_sf(crs = st_crs(26904))

It plots with geographic coordinates. Nothing I've read seems to work. I've checked the st_crs and it is correct. The geometry coordinates are in the correct units so it must have to do with ggplot somehow.

Mahalo.
J.

I found the answer. You have to ALSO change the datum.
This works.

p1 = ggplot() +
geom_sf(data=HI_L0_26904, aes(geometry=geometry, fill=NAME)) +
coord_sf(datum = sf::st_crs(26904), crs = st_crs(26904)) +