In case you have a special discount code, you can apply it to your bot
Navigating to the 'Coupons' tab on the 'Settings' page will display a list of coupons currently active and if there are none, a big blue 'Enter coupon' button.
Click it, enter your code and click 'Verify'.
After verification the coupon description will be shown to you and you are able to click 'Apply' to apply the coupon. That's it.
Now, your 'Coupons' page should have updated the coupon details, also showing on what date it expires.