The goal is to find out if the interrupt routine is ever being visited. Putting a message to be printed inside there is one way to prove that. If you are successfully printing messages yet the message inside the interrupt routine is not being printed then the interrupt routine is not being visited. Your interrupt is used to time the pulses of the data stream in order to decode the message. No interrupt - no message to drive the rest of the process.
Next is to find out why it isn’t being visited, The problem is either no proper data stream (IE poor logic levels [Xiao 3.3V Nano 5V] or data stream on the wrong pin) or something improper in the interrupt setup (your code must identify the interrupt service routine and say which pin is to be used) . Earlier I went thru the library to see what those calls where but it’s been so long that I no longer remember so it’s up to you to identify those.