How to auto enter password when prompted, for a script that runs as root?

I run this script in Better Touch Tool via a touch button:
sshuttle --daemon --pidfile=/tmp/ -r 0/0

But sshuttle requires my user password so nothing ever happens, not even a popup.

So I put that line in an automator script, so I can "tell" terminal to open and run it, and then I get terminal prompt so I can manually enter my password and it works.

But ideally I just want BTT to run it without needing to enter the password.

Does anyone know how? I followed the instruction on the sshuttle site to enter the command in sudoers file but it's not working: Usage — sshuttle 1.1.0 documentation