Cast with your computer screen
Cast your complete screen on chrome os, mac, window.
Go to the chrome
Then you find the three dots on the right side of the google
Click on three vertical dots
You will see the given source , click on that select you want to cast tab, cast desktop, and cast file.
Select the chromecast your device that you want to cast on your screen
If your device has the in built chromecast option, then select that .