I just went to PBS.org and clicked on "Find another PBS station", then on "Station Finder". I tried a couple of Florida PBS stations, clicking on their TV schedules, and didn't find "Underdogs" listed, but I don't know what city you are in.

You might try other stations in your area. If you don't find it tonight, you should probably contact your local station and ask if and when they will be running it. I also found the place on PBS.org where you can purchase the video.