To detect the browser version on the client machine, your script can analyze the value of navigator.appVersion or navigator.userAgent.
Example
console.log(navigator.appVersion)
Output
This will give the output based on your browser and its version −
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/77.0.3865.90 Safari/537.36