You have to match levels and impedances. That’s frequently done using an audio transformer. What is the output impedance on your radio? It’s probably 8-16 ohms, but your manual should say. Is it a speaker output or a headphone output? They have different levels.
What are the specs of your audio input on your PC?
Amazon sells cables that match outputs to inputs, but you really need to know what you’re matching first.
Another way to do this is by placing a speaker and microphone close to each other and letting them couple audibly, but there are drawbacks to that as well.
Good luck, Jacob!