@Chileseattle
Roku doesn't make the apps on Roku, nor does Roku control the functionality of the apps that are developed. Neither, by the way, do Amazon make the Fire TV apps, nor does Apple make the Apple TV apps, nor does Google make the Google/Android TV apps. So if there's no app for a particular platform, such as WNBA League Pass for Roku, then you should ask WNBA why they don't have a Roku app.
From what I can tell, they don't make an app for Google/Android TV (though they do make a WNBA app for Android tablets and phones). I don't see one for Fire TV either. And I'm not seeing one for Apple TV either, though I do find a WNBA app for iOS and iPadOS.
DBDukes
Roku Community Streaming Expert
Note: I am not a Roku employee.
If this post solves your problem please help others find this answer and click "Accept as Solution."