Did you try apt update and apt search? Is it in the repositories you’re searching? Do you need to add a repository and/or build it from GitHub?
The reason Kali is a meme is because it’s intended for professionals but often used by newbies, and you’re asking a rather basic question about package management.
You’re running a live image, so the list of packages in the external repositories may be blank depending on how Kali does its defaults. Having apt fetch a package list is a very easy first troubleshooting step.
You need to run sudo apt update before trying to install things. Notice that you'll need to do this every time unless you installed Kali with some permanent storage. Which is why it's usually a better idea to just use your day-to-day Linux box for stuff, Kali is for when you want to not leave traces and not allow any backtrack to get to your actual system, for most non red team related stuff you don't need Kali.
I haven't used Kali Linux before, but hcxtools is available in the Debian repos so presumably your /etc/apt/sources.list is invalid (probably the LiveUSB has disabled non-iso sources). Can you post what is in that file?