Protonmail Bridge on Linux
https://proton.me/support/installing-bridge-linux-deb-file
https://proton.me/support/bridge-cli-guide
Download .deb file from page above
wget https://proton.me/download/bridge/protonmail-bridge_3.9.1-1_amd64.deb
Prepare the Environment
sudo apt-get install build-essential libgl1-mesa-dev
Install Proton Bridge
sudo apt install ./protonmail-bridge_*_amd64
Configuring Proton Bridge
protonmail-bridge --cli
login and enter the main proton credentials
change mode and enable “Split mode” which will allow the inbox to be split to use the identities