I installed the Arduino nodes: https://flows.nodered.org/node/node-red-node-arduino
I imported the flow. The example SimpleDigitalFirmata sketch was uploaded to the Arduino Uno (even though I want to use an ESP32). And the COM3 (which the Uno is connected to) was set in "Edit arduino out node." (Also, the pencil icon was clicked and searched for COM3 and selected.)
Now it just stays on "connecting."
Am I missing something? Thoughts?