How do i flush the toilet on a 2004 27bh?

I bought a used 2004 27bh this week and the toilet has a place to fill it with water, but no release to dump the water out.

The toilet lid has a picture on it showing a foot pedal on the front, but there is not a pedal and no place where the pedal could have broken off. It doesn't look like there could have been one.

Any ideas?