The campaign is still open or not? Because as what I've seen in the spreadsheet, the next payout will be on last 03/11/2018 and I was waiting for another update.
Even if there's an open slot or not still, you will not be accepted due to your rank. Only Sr. and up are able to join in this campaign so, make it possible by ranking up. But it might difficult for you since you still not get even single merit.