The long awaited Marshmallow update is available for the Canadian LG G3 vairent.
You will have to connect your phone to your PC and run the LG PC Suite.
If you have not downloaded it already, here are the instructions
Google "LG PC Suite"
On their website go Smartphones> LGD852(G3) on step two, click "Download PC Suite"
In the software there's a tab that says "Upgrade Check"
Click that and give it a few minutes. You have the option of updraging right away or doing a full back up and then upgrading