To activate a Promo code you have to Sign in first.
You’ll get on your account home page upon authorization.
Click the “Change Plan” button in the upper right of the screen.
That click will take you to the plan selection page. Pick a Pro or Premium plan.
The “Buy” button will take you to the membership purchase page:
Fill in the “Apply promo code” field with the code you’ve got and press the "Redeem" button.
Once you’ve applied the code, the discount amount will show up. The “Pay” button will redirect you to the Credit Card Payment page.
If you have any questions left, feel free to contact Proficonf support service or write to email@example.com.