Because you didn’t follow EXACTLY the instructions.
It is very clear there specified that you need to run Tor as a service in your local PC (where is installed Sparrow) and connect Sparrow through that local proxy 127.0.0.1:9050
You can use also local IP of your node, without Tor.
But you will need to open port in ufw in your node and set a static IP for you node… so more tinkering.