ON1 2019... Does it work with the pay version of Nik Collection?

Have been using the free NIK COL. with LR and ON1 2018 with no problem what’s so ever.
How about NIK COL. with ON1 2019? Cant see any information about that on your website?

I just checked, and the Nik (by DxO) modules are there when you right-click a image in ON1 2019.

I had to add them one at a time by selecting “Send to other application” and pathing to them. Are you saying that yours just showed up LesC?

Yes. I didn’t have to do anything at all.
What you might have to do (if Nik was installed before ON1 2019 was launched), is to install Nik again. But I did not have to add any paths at all.