JSAUX USB Type C to 3.5mm Female Headphone Jack Adapter, USB C to Aux Audio Dongle Cable Cord Compatible with iPhone 17 Pro Max/16 Pro/15, Samsung Galaxy S24/S23/S22 Ultra, iPad Pro, Pixel 9/8 Grey

get a female 3.5mm to usbc audio adapter plug it in to the usbc port on the osmo and try and see if that works. https://www.amazon.com/Headphone-Adapter-JSAUX-Compatible-Samsung/dp/B07XYQ2ZKH?th=1

I assume you don't have any other wired headphones lying around you could use to test if the headphone jack on your phone is actually functional? It might be that it somehow got damaged because yes, any headphones with a 3.5mm jack should work fine. Alternatively, you could buy a USB-C to headphone jack adapter, something like this