To get a license key from one of your previous purchases, just click here:
https://www.steganos.com/en/selfservice
All you need is the email address you used for that purchase.
Please note: Licenses for Steganos VPN Online Shield, Data Safe 22, Password Manager 22 and Privacy Suite 22 are stored directly in your mySteganos account. If you want to check those, just log in to mySteganos.