Hi, @t.leite. According to distrowatch.com, Endless is based on Debian, so follow the instructions for Debian if Endless’s package/software manager doesn’t have Brave included. For convenience, the Linux install instructions are at:
If you need more help, just say the word. If need be, I can create a virtual machine running Endless to see exactly what you do (or at least as close as possible shy of screen sharing). Please do note that I’m just a fellow user, but I’ve installed and used Brave in a bunch of distros of Linux, as well as Windows, macOS, and iOS.