Usually, antivirus applications are not needed for Google Chromebooks. They come with built-in malware protection and virus protection with several layers of security. For following steps on How To Install Antivirus on Chromebook as,
Chromebooks have an automatic update system:
Here are some alternative methods to safeguard your Chrome book device:
Keep Developer Mode disabled.
Keep your Chromebook updated.
Installing antivirus on Chromebook: