There are two ways to get audio from your TV to the receiver.
1. If both the TV and receiver have ARC then plug the HDMI output of the receiver into the HDMI input on the TV labeled ARC. Turn ARC on in the receiver menu. Select it as your source in the receiver.
2. You could also use the optical audio output of the TV into one of the optical inputs on the receiver.
You may have to turn it on, turn the TV speakers off, and change the output type in the TV menu. On the receiver you may have to assign the optical input you use to an input such as TV or Video 2.