Why is no sound coming out my iPhone. The only sound that works is the ringer and when I have headphones hooked up?

I have a iPhone 6s. And recently no sound has been coming out my iPhone. The only sound that works is the ringer and when I have headphones hooked up. When I try to watch YouTube or Facebook videos or even try to talk on the phone I will hear no sound. My phone is updated to IOS 12.

Go into settings and make sure everything in the mixer is unmuted, and make sure the little switch on the side is not on vibration. Also check that you haven't or someone hasn't downloaded some kind of audio modifying apps on your phone, hope this helps!