iPad Air 4 Earphones Adapter

Hi. I am having trouble listening to audio from my iPad Air 4. Recently I bought a third party adapter (type-C to audio jack) since I don’t have any type-C earphones. However it happened to be not working and the sounds only came out from the build in speakers. I can confirm that the adapter is fully working because I have tried connecting it to my other devices. But for my iPad it seems like the earphones somehow aren’t connected to it. Is there any settings or solution should I be considered.