The tractor is trying to tell you what regen level the dpf filter is in. If one of the lights has an exclamation point ! in it and is solidly on and not blinking, turn the tractor off and call the dealer. Otherwise you may be able to do a parked regen. If you can't find the directions and your manual, look for a sticker on the fender or in the cab that says something like " If you hear buzzer and lights etc, it will tell you the parameters needed to do a parked regen.
The tractor will have to warm up first. If you can't find manual, we need to know which lights are blinking and how fast the buzzer is sounding to help further.