In youtube video the ad appears ,i use last adguard beta,android 7
There is no such option. Maybe you can take a picture and post it here?
What? YouTube app can be filtered by AdGuard for android, with latest version 12.34.55 i see ads with adguard actived, but why i see ads? This program is made for deleted ads. As I already told you, you go in setting>Apps>Scroll down until see Youtube app and open it>i click on deactivates button>restart your device. Next go to store and disable autoupdate after you search youtube app!It varies from device to device. I personally don't recommend turning off updates for apps or downgrading apps due to security.
It's likely the YouTube app can't be filtered by AdGuard for Android anymore.
In your case you need to go to YouTube app settings instead of browser.Try resetting app preferences. Go to Settings->Apps, choose from menu Reset app preferences and confirm Reset apps. This will reset all app preferences.
To reset preferences for specific app (e.g. Browser), choose it in Settings->Apps and press Clear defaults button in Launch by default section.