Manual Transmission, I presume...
Yes it is, it's a bolt (IIRC 13mm) on the vertical face of the gearbox. The oil should be level with or no less than 5mm below the threads:
Park on a level surface.
Remove bolt. There WILL be a small amount of oil trickle out, this is normal and does not mean the level is correct.
Top up with oil (Hypoid gear oil EP80 or similar) - overfill and allow the excess to trickle out. Do not overfill, you will blow the output shaft oil seal on the box.
Refit bolt and torque up.
Job done