Unfortunately, this is a new promotion included with the purchase or upgrade of Nik Collection 2 by DxO only, and is not offered retroactively. The price is not the same, so no free license will be offered.
You paid in the past 69 USD / 59 GBP.
The new pricing for Nik Collection 2 by DxO including DxO PhotoLab 2 ESSENTIAL Edition is 149 USD / 125 GBP.
So, the upgrade including DxO PhotoLab 2 ESSENTIAL Edition is as follows: 79 USD / 69 GBP.