As others indicated, you need to buy online or at a retailer then keep your receipt (as proof you have the pass) until you get the sticker in the mail. Usually takes less than a week to get it in the mail.
If you belong to a club which hopefully you do go to AWSC website and purchase for discounted pass. You can print receipt or do what I did and do a screen shot.
As stated above. Best to join a Wisconsin club, then trail passes are $10 going through the AWSC website (print receipt to used until passes/stickers are mailed to you)