version 10.6 is the latest stable, download the betaflight-configurator_10.6.0_amd64.deb file and install it from the prompt (Terminal window),
> sudo apt install betaflight-configurator_10.6.0_amd64.deb
You may get some dependency warning/error messages, just to be on the safe side, run the following command,
`> sudo apt --fix-broken install’
this will further install any additional libraries that might be required to run your program.
You may want to read this thread, Getting started with Debian GNU/Linux and Gnome as well as Setting up/configurign Librem PureOS laptop.