My phones speaker isn’t working.

Look at the grille; is it blocked? Usually this is a hardware problem. While you can replace the phone at an Apple store for a substantial discount from what you paid for it, you might consider this as an excuse to upgrade to a newer model.

Most likely it’s a hardware problem. But have you tried the obvious, like the Mute switch, Do Not Disturb settings and the volume controls?

Which speaker isn’t working? The one at the top of the screen or the one on the bottom edge?