Welcome to the forum!
My interpretation of what you want is to play sound from the TV through the speakers connected to the Denon, and to do that, you've connected an HDMI cable from the TV to the Denon. Is that correct?
If so, that won't work. Although newer components can send audio back and forth through an HDMI connection (using what is called the Audio Return Channel, or ARC), your Denon is older and does not support that. Therefore, the HDMI audio is only one-way, going from the Denon to the TV.
To get sound from the TV to play through the speakers connected to the Denon, you'll need to make a separate audio connection from the TV to the Denon. You have two choices: the "DIGITAL (AUDIO OUT OPTICAL)" and "AUDIO OUT" connections on the TV. The best option is the digital optical connection, as it can provide full 5.1 surround sound. You'll need an optical cable for that. If you don't have one, they cost around $5-$10.
Does that help?