Create a SIM Card

Use BalenaEtcher to create a SIM card. 8GB is adequate for Raspbian if you don't install too much on it.

Networking

sudo raspi-config. Join WiFi. Optionally, change the hostname, here or via sudo nano /etc/hosts (followed reboot).

Enable ssh (below)

Discover the IP address. On the Pi: hostname -I. Or install Bonjour via sudo apt-get install avahi-daemon libnss-mdns. (Seems already to be installed…)

From a local laptop, ssh-copy-id pi@<IP-ADDRESS>

Enable ssh

Three methods:

1. Use the UI.

2. From the command line:

   sudo systemctl enable ssh
   sudo systemctl start ssh
   

3. Create an empty file named ssh on the boot partition.

Disable password login

sudo sed -i 's/#\\?ChallengeResponseAuthentication yes/ChallengeResponseAuthentication no/' /etc/ssh/sshd_config
sudo sed -i 's/#\\?PasswordAuthentication yes/PasswordAuthentication no/' /etc/ssh/sshd_config
sudo sed -i 's/#\\?UsePAM yes/UsePAM no/' /etc/ssh/sshd_config
sudo /etc/init.d/ssh reload

Change the hostname

sudo nano /etc/hosts
sudo nano /etc/hostname

Install FPR client

Download and build.

Install ngrok