Click the “rewards” button on the lower right of your screen.  It may prompt you to log in or sign up.  Follow the instructions it will give you to do so.

Once you are signed in, your points balance will appear at the top of the rewards window. 

Go to “Ways to redeem” and click “Order Discount”.  This will give you $1.00 for every 100 points. 

Go to “Your rewards.” Click on the Coupon listed to apply that discount to your order.  

Place your order as usual, the discount should automatically appear when you check out.