There are a few possibilities:
* You might be thinking of "Superman/Batman: Apocalypse": This is an animated movie from 2010. It's available on various streaming platforms like HBO Max, YouTube, and Amazon Prime Video. You can search for it on these platforms.
* You might be thinking of "Batman v Superman: Dawn of Justice": This is a live-action movie from 2016. It is available for rent or purchase on platforms like Amazon Prime Video, YouTube, Google Play, and Apple TV.
* You might be thinking of a different movie altogether.
Please double-check the title and provide more information if you can.