To see a list of all your purchases, and re-download the software, you can login to your PSEngine account at https://psengine.co.uk/
Once logged in, you will see you can access Account | My Dashboard
Under the list of your purchases, you can see View details and downloads.
On the details for the product will be any download links and license keys for your purchases or subscriptions.
Click on the version you require for your device to begin downloading.