How To Find Out My License Key?

Hi

I tried to download and install Bitdefender 2016 for Mac and did that successfully. I have already a Bitdefender Total Security Multi-Device 2015 subscription for 2 years and want to use this subscription (which is registered in "My Bitdefender") for Bitdefender Total Security 2016 and want to move it to Bitdefender Central (which I have to use instead of My Bitdefender apparently). There is following dialogue:

"Do you have an old license key, but you want to try out our new line of products?

Insert it here and we will get you fixed with a subscription for our latest 2016 products."

Great, but I have no idea how to find out my Bitdefender Total Security Multi-Device 2015 License Key. In My Bitdefender, you can't find out the License Key and in the mail that I got when I ordered Bitdefender Total Security Multi-Device 2015, there is only a dialogue that I got the subscription with my Email-address.

So my question is now: how can I find out my License Key for my Bitdefender Total Security Multi-Device 2015 which i subscribed in spring 2015.

Thank you very much and

kind regards,

Jan Frei

(That's what I wrote to the support - I didn't get an answer yet.)