Login by Product Key – Customer Portal

As we can login LDK-EMS in two ways:
Vendor Portal: login by username and password
Customer Portal: login by ‘Product Key’

-> Vendor Portal
We login in Vendor Portal using the following Input XML code:

<?xml version="1.0" encoding="UTF-8"?>

-> Customer Portal
Question: How do we login using the ‘Product Key’? What should be the Input XML?
Answer:   We DO NOT use any Input XML when logging in with ‘Product Key’ instead we use QUERY STRING:

Uri(" keyxxxxxxx”);