You don't select the HDMI-ARC input of the TV you select the antenna (or any other input) so you get a picture. The audio return channel sends the audio to the receiver. If you have all your sources connected directly to the TV you could also use the optical audio output of the TV instead and save the HDMI input for another source.
You usually have to turn ARC on in the TV menu. You may also have to turn the TV speakers off and set the output to bitstream to get it working properly.
In the receiver you may have to assign ARC to an input name in the input menu.