That package will not work with Namib which is an Arch based distribution. That URL is a download for a deb file. Files packaged like that work on debian base distributions of linux. A package for Arch will not not be prepackaged but in a compressed file format and you have to install using the files inside with the terminal using make config make and make install commands. Arch is not as simple as installing in Mint Ubuntu or Debian. You will learn a lot more using Namib because even though it is a lot easier than basic Arch it still have some old fashioned parts that are like years ago where you have to learn to appreciate the full experience. Heck think of it this way, you will get a lot smarter faster than if you were using a total beginner distro like Mint and you'll make mistakes and have victories and learn a little each time. I recommend going to the Archwiki and read up on this or whatever topic. The arch wiki has a ton of information users from all linux distros use to find out how to do stuff. I recommend visiting there and bookmarking the main page so you can find it again simply. Here's a link to it for you https://wiki.archlinux.org/. Hope you stay with Namib, it's my favorite Arch based distro since Antergos was abandoned. 😀