These changes come with version 2.1.3 of the app on the Play Store but your device should also be capable of the Google Assistant feature and should be running at least Android 5.0 Lollipop. This will be achieved by placing direct links within your Phone, Contact, and Messages apps.
Jan Jedrzejowicz, Product Manager, Phone app of Google Duo. However, this would depend on if you and the person you are video calling are on a carrier that supports ViLTE video calling. Google is now in the midst of cooperating with operators and manufacturers to make video calling a reality on a wide range of Android devices over time.
If you're outside of the U.S., you're also going to miss out - for the time being, at least.
Naturally, the first phones to get access to this new integrated video calling experience is Google's original Pixel, Android One phones, and Nexus devices. So, be on the lookout if you are not already using one of those phones mentioned here.
After an absurdly long amount of time, Google now lets you send music and videos to Chromecast-enabled devices using the Google Assistant on your phone.
That being said, with cheap data rates, people are making the most out of video calling services today. The latest app to receive the Google Assistant feature is Hulu for Android TV. With this integration, you will be able to make video calls in addition to being able to make voice calls. If not, Google Duo will connect your video call to anyone with the app installed.