Purchasing 1 month Key

[Swallowboy]

I still have about 20 days on my sub but I want to purchase 30 days key to use the available discount code 

 

how can I make it and to be added to my current sub ?

[Eliphas]

You can't.

But the new key will not start until you redeem it, so can buy now with the discount code and wait to use it until your current sub expires.