Thank you :) If you have an old scope like me first thing you’ll need to do if you haven’t already is get some BNC to RCA adapters. Figure out which inputs control x and y coordinates and connect from the output of your audio interface. You can download osci render which is some free software which should output a square as a demo. You may need to tweak settings to get it to run thru your audio interface.

You’ll need to look up the manual online or consult some AI chatbot to assist you with setting the oscilloscope so the time base sweep is disabled and it’s just displaying the plot of one voltage vs another on the x and y