Can't update Beta app on chromecast w/GTV

Running beta app on chromecast with google tv, version Beta (4.13.102). When I try to update it says "Unknown apps can't be installed by this user". This has always worked before
Update: Looks like the app needs to come from google play now, not within the app itself on the Support page. Got it and deleted the old version.

You have to go into the OS settings and enable installing unknown apps

I updated my post to say I got an updated app from google play.

So the app can be updated like all other apps in CCWGTV now, and also by enabling install unknown apps? Does enabling install unknown apps cause the app to show the update option on the Support page as it used to? The new app from google play does not show that option. Sorry, but I'm confused. Thanks for the response.