I use Firefox and the add-on Video DownloadHelper to download video from web sites.
Unfortunately, from Firefox version 52 one has to install Video DownloadHelper Companion to have it working.
In the page https://www.downloadhelper.net/insta...?version=1.2.1 there are files and an how to but not what I use to get for Opensuse Leap.

I don't want to jeopardise my install, could you tell me how to install it?