If, when trying to activate Ashampoo software through the Ashampoo app, you receive a message that the entered license key has already been assigned to an Ashampoo account, you are likely not logged in with the email address used at the time of purchase in the Ashampoo app.
In this case, click the user icon at the top right in the Ashampoo app and select "Log out." Then please log in again with the email address used at purchase in your account. You will then find the software available for installation under "Your Collection."