Any tips for non invasive ways to be able to listen to music through AM radio from my phone in my 1988 Dodge Ram B350?

This is my first time posting in this subreddit so I’m hoping I’m in the right place. I just got this beauty a few days ago and I have a lot of plans for her but my first small project is a more convenient way to listen to my music.

I’m currently using a portable Bluetooth speaker and it gets the job done but I’d love to be able to use the vans speakers since they work great. I might redo the whole radio at some point in the future but I really do love the original appearance so I’d like to avoid that for now. I’ve looked into RediRad but they seem pretty hard to find so that’s why I ended up here in hopes there might be something simpler I could buy or put together myself.

Any advice is much appreciated(: