Yes, it's a 1200km ride, within a 90 hour time limit.
To qualify you must ride 200, 300, 400 and 600km sanctioned events in the months leading up to the PBP.
If training, you must prepare yourself to basically be self supported. There are only a few designated support areas. You can't have a support car riding behind you passing your food or drink whenever required. Many people buy their food along the way, etc.
I am considering this for next year, like yourself, I am a little concerned, because although I have ridden plenty at night , I have not ridden through the night, or for more than 10 hours straight, let alone 60-70 hours.