Question

Ah yes, 48khz, Sorry. There is no other options except 44.1 on Studio One 4. Is their any way to add it?

Answer 1

Please rephrase that.
In anycase, make sure your interface can process higher than 48 khz
for that you'll most likely need to go into your computer sound settings to make sure the proper drivers are installed, perchance your interface CAN process more, but is being bottlenecked

Answer 2

I’ve used 48 kHz plenty. Gotta have it set in the Audio Device Setup and the Song Setup window when you start a session....