I don't know about your specific model but most tractors are the same. If it is gear drive, Put the gear and range selector in neutral and push the clutch all the way in while sitting in the seat. It should start unless the PTO lever is engaged. Some tractors will not start if the PTO is engaged.
If it is HST drive, you should be able to just put the range selector in N and PTO disengaged, HST F / R pedal in neutral. Rock it back and forth with the key in start position to make sure the micro switch is positioned correctly.
It should start unless the seat occupancy switch is bad. Maybe try some jumper wire and jump the seat switch.
I like my Kubota B26, it starts without any micro switch seat occupancy, range selector can be anywhere but pedal must be in neutral. Try to move it from the ground and it dies.