On Linux, communication between the NymVPN app and the daemon is authenticated, so the app requests the user password to connect to the daemon. Under the i3 window manager that password prompt never appears unless an authentication agent is running, so the app cannot connect. For i3 users, you need to have policykit-1-gnome installed and the authentication agent running for the app to be able to prompt for the user password.
To ensure authentication runs properly on your Linux device, follow the steps below to install the GNOME Polkit authentication agent under i3.
Setup
Add the following line to your ~/.config/i3/config file:
exec --no-startup-id /usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1
This ensures graphical authentication dialogs (for sudo and privilege prompts) appear. Make sure policykit-1-gnome is installed.
Implementation steps
Step 1: install the agent
sudo apt install policykit-1-gnome
Step 2: edit your i3 config
Open ~/.config/i3/config and add:
exec --no-startup-id /usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1
Step 3: reload i3
Press $mod+Shift+r to reload the config, or restart i3. You're all set.
Related questions
Why does NymVPN ask for my password at all?
The daemon manages your network configuration, so the connection between app and daemon is authenticated with your user password as a security measure.
I use a different minimal window manager. Does this apply?
The same requirement applies: a Polkit authentication agent must be running for the password prompt to appear. The GNOME agent installed above works under most window managers.