To use the Signal desktop app, Signal must first be installed on your phone.
Or visit signal.org/install from your phone
Linux (Debian-based) Install Instructions
# NOTE: These instructions only work for 64-bit Debian-based # Linux distributions such as Ubuntu, Mint etc. # 1. Install our official public software signing key: wget -O- https://updates.signal.org/desktop/apt/keys.asc | gpg --dearmor > signal-desktop-keyring.gpg cat signal-desktop-keyring.gpg | sudo tee /usr/share/keyrings/signal-desktop-keyring.gpg > /dev/null # 2. Add our repository to your list of repositories: echo 'deb [arch=amd64 signed-by=/usr/share/keyrings/signal-desktop-keyring.gpg] https://updates.signal.org/desktop/apt xenial main' |\ sudo tee /etc/apt/sources.list.d/signal-xenial.list # 3. Update your package database and install Signal: sudo apt update && sudo apt install signal-desktop