Tox is a peer-to-peer, end-to-end encrypted, instant messaging protocol, with end-to-end encryption as its default and only mode. µTox is cross-platform: Primary support for Windows 7+ and Linux, ...

Following are barebone compilation instructions. They probably won't work but #utox on libera.chat can probably help you out. If you're looking for it to "just work" you're going to want these ...