Before you activate the Personal Data Marketplace (PDM), navigate to the section Marketplace, read the Marketplace Rules and then activate the Marketplace. Now you will see all available offers. Select an offer that interests you and see which of your data will be used for what purposes. To accept it, you may need to share additional information. You can enter and save the required data directly on the marketplace interface. 

In the section My Data under Profile you can check and complete your profile data.