Easy as Pi, Your Own VPN at Home using a Raspberry Pi & Tailscale

How to easily create your own free personal VPN using Tailscale and a Raspberry Pi even if you have a dynamic IP address (not a fixed IP address) or no public IP address (behind GCNAT) and without opening ports on routers.

Notes:
If you click the top check box when setting up the options for the Raspberry Pi SD card you should be able to use raspberrypi.local (the default host name) to connect to the Raspberry Pi if you don’t know its IP address. In which case, our example would be:
ssh [email protected]
or search for The Adafruit Raspberry Pi Finder to use that.

Terminal commands for updating and upgrading the Raspberry Pi:
sudo apt-get update
sudo apt-get upgrade -y

Tailscale can be set up using these commands on the Raspberry Pi and other Debian/Ubuntu based Linux computers:
curl -fsSL https://tailscale.com/install.sh | sh
echo 'net.ipv4.ip_forward = 1' | sudo tee -a /etc/sysctl.conf
echo 'net.ipv6.conf.all.forwarding = 1' | sudo tee -a /etc/sysctl.conf
sudo sysctl -p /etc/sysctl.conf
sudo tailscale up --advertise-exit-node

Update: I would like to say that I can't guarantee that WiFi calling will work through a VPN service when abroad as it seems to vary by phones and mobile phone networks.