The Sprinter cutaway chassis usually has a spare tire mounted underneath behind the rear axle. However I understand that some levelling jacks added in that area and some models with bath on the passenger side have a transverse sewer connection in that area, preclude having the spare. Alternative is a hitch mount carrier.
Fortunately my 2016 24ST has the spare.
U.S. Coast Guard retired- 1956-1985
2016 Siesta 24ST
1972 Moto Guzzi Eldorado