Android: The YouTube app can be requested in CloudLocker > Request Unblock. The safest way to use the YouTube app is with CloudLocker VPN, which removes the adult content.
Apple iOS: Global iOS blocks YouTube, however you can request that it be unblocked.
The Blue browser: does not block apps. Apps are controlled via age restrictions settings or via parental control whitelist. CloudVeil Blue install instructions show you how to block the YouTube app, which is recommended for most users.