For your security, eBay requires that Just Ship IT does not ask you for eBay username or password.  Instead, Just Ship IT requires that you login on to a special eBay web page which creates an eBay token that only Just Ship IT can use to access your eBay account. 

After you login and agree to the terms on the eBay page, a token will be created and sent securely to the Just Ship IT license server.  The token is then deleted from the Just Ship IT server, and you are ready to use Just Ship IT to connect to eBay.