Audio not playing through earphones

So I was trying to listen to music from my iPhone using Bluetooth earphones but despite the earphones saying they were connected to my phone, the audio continued to play through the phones speaker however since the earphones are old I assumed it was just something wrong with them. Later however I tried listening with regular earphones and the audio still only plays through the speakers. I’m pretty sure my earphones work so is there something wrong with my phone? What should I do?