Please enter the Product Key and press "Submit Request".
You can find the Product Key in the Product Registration wizard. It is presented as five groups of eight characters separated by dashes ("-").
The Product Registration wizard is presented to you when the free trial period of the product is over. Products may allow pre-registration where you can start this wizard from the Help menu or similar means. Note that this is not same as the serial number that is required during installation of certain products.