Install Lutris
Ubuntu:
$ sudo add-apt-repository ppa:lutris-team/lutris
$ sudo apt update
$ sudo apt install lutris
Elementary:
$ sudo add-apt-repository ppa:lutris-team/lutris
$ sudo apt update
$ sudo apt install lutris
Xubuntu:
$ sudo add-apt-repository ppa:lutris-team/lutris
$ sudo apt update
$ sudo apt install lutris
Fedora:
$ sudo dnf install lutris
Open Lutris with Proton
$ LUTRIS_ENABLE_PROTON=1 lutris
Note: You can set this as a shortcut by making an SH file and linking it to your menu. The SH code is below.
#!/bin/sh
LUTRIS_ENABLE_PROTON=1 lutris