Are you looking to sign up to Wonder PRO? Here's how:
Go into your Wonder space for whom you would like to sign up for PRO seats and enter the menu (icon in the lower left corner). You should now see the "Subscribe to Wonder" button (see screenshot)
Next, select the number of PRO seats you would like to sign up for. Note that the minimum number is 3 and depending on your location, the price and currency may differ. Once selected, click "Activate Pro!"
Now enter your email address, country and Zip Code and press "Continue". If you have a discount code you can click the "Add discount" button on the left-handside.
You can either pay with PayPal or with a Credit Card. Enter your payment information and click "Subscribe Now", that's it!