Question: how to change pro tools 12.8 to 12.7??

[Newtoprotoo]

Hi
Would really be helpful if somebody can give me advice to solve my problem situation

I just bought pro tools 12.8.1 (if its not HD its LE right??) from the avid web store. Now I got a MacOs Sierra 10.12.2 and I knew pro tools 12.8 is not compatible but It is the only pro tools you can buy through the avid web store
(I could not find any other option/version to buy) So my thinking was all people that have a earlier computer what do they do?? Avid cant be only selling for new computers so my thinking was/is that you buy 12.8 and then get access to all the earlier versions of pro tools or at least the 12.x versions.

How do one find/get pro tools 12.7.1 (which if Im not mistaken is the one compatible with my Sierra 10.12.2)???
Can one not impliment/transfer ones licence (I havent downloaded pro tools 12.8 from my pro tools account get) to a earlier pro tools version???

Many thanks