You can control Chromecast using Google Home/Google Nest Hub.
To use Google Home/Google Nest Hub, you need to set up at first. For details about setup, please refer to this Google Home Help.
Also, if you did not set up with the Hulu account at the time of the first setup, you need to set later.
How to link between Google Assistant and Hulu account:
*Make sure your device is the same Wi-Fi network as Google Home.
1. Open the Google Home app.
2. Select "More settings" from the Home menu.
3. Select "Videos and photos."
4. Select "Link" and "Link account."
5. Log in with the Hulu account.
For details about a link to the Hulu account, please refer to this Google Home Help.
2. Select "More settings" from the Home menu.
3. Select "Videos and photos."
4. Select "Link" and "Link account."
5. Log in with the Hulu account.
For details about a link to the Hulu account, please refer to this Google Home Help.