single ring is irrelevant. Your Fuji has this crank/bottom bracket: Crankset ProWheel composite resin/steel, 44T
Bottom bracket Sealed Cartridge Bearing ST
The crank arms both can be removed from the crank axle. Thus, it's a three piece.
With a one piece crank, the crank arms and axle are...................one piece.
__________________
Bacchetta Giro A20, RANS V-Rex, RANS Screamer