And here, below, is the configuration for adding it to your search engines list (and even make it your default search engine if you wish to do so). All the info is contained in one URL. The reason it is so long, is because it contains also the little icon for the Qwant search engine.
I used the site "Ready2Search", which allows you to create instalable search engines "on-the-fly":
You can customize the Qwant settings to your need:
Or create your own search engines.
CAVEAT: setting an icon is a bit tricky, because you need a 16x16px image and the transparency does not seem to work too well, but I haven't diged much into that.