@greatgazoo215 I'm going to take a guess and presume you are using the Linux version of Opera rather than the Android version, and move your post there, as I'm not aware of a method to do anything about video on Android (though if you did install from the Play srore let me know).
There are instruction here in the Opera for Linux forum on how to identify and install the correct package of Chromium codecs for your version of Opera. Is this an ARM based Chromebook or one of the Intel ones? Make sure the package matches your processor type, if 6you can't find it in your package manager.