Connect to your customer account on 

Click on "My manufacturer accounts":

Click on "Add / Request a manufacturer account":

Select the manufacturer to add to the list and click "Next".

Enter the account number and password provided by the manufacturer and click on "Send my request" :

The manufacturer's account is added.

Update your license pack: Click on "My current pack".

Check the box corresponding to the new manufacturer:

Choose the quantity of licenses and click "Next".

Follow the payment steps (download the IBAN for bank transfer, or payment by credit card).

A summary of the order appears.

Once the information has been verified, validate.

The new invoice is issued and available by clicking on its number.