I don't think you can add it by yourself, it's a website. It's a good suggestion. I personally don't use the website you can use extensions to your browser to customize your
New Tab Page.
I just use the default
It may do a lot of good for the ZorinGroup to add alternatives, not just the Duck, but various other privacy-minded engines.
The Duck has recently come under fire for not being as privacy minded as claimed... It raises serious questions as to whether a Privacy minded Search Engine can even exist.
You can control what search pages open using Firefox settings (or the settings in whatever browser you use, if you don't use Zorin's default Firefox). In Firefox, just set "Home" to open whatever "Custom URLs" you want on startup:
As you can see, my Firefox is set to open three Bing tabs on startup, but there is no reason you can't set your browser to open DuckDuckGo or any other startup pages our prefer.
you can try using metager or swisscow.