For Debian (and downstreams) the packages can be installed from the official repo. First add the repo to your system with:

sudo apt-get update
sudo apt-get install ca-certificates curl gnupg -y
curl -sSL https://pkgs.netbird.io/debian/public.key | sudo gpg --dearmor --output /usr/share/keyrings/netbird-archive-keyring.gpg
echo 'deb [signed-by=/usr/share/keyrings/netbird-archive-keyring.gpg] https://pkgs.netbird.io/debian stable main' | sudo tee /etc/apt/sources.list.d/netbird.list

Next Update the cache, and make sure your system is up to date.

 sudo apt-get update

For CLI only (headless) use the following package:

 sudo apt-get install netbird

For the GUI Version, use the following package: 

sudo apt-get install netbird-ui

Now, you need to authenticate, see the Linux Authentication FAQ