You can use the following Javascript in "Userview Builder > Settings > Custom Javascript" and change the favicon_my.ico image filename accordingly.

Then copy your .ico image into "...\apache-tomcat-8.5.23\webapps\jw\images\" folder.

 

// Set the Favicon as the page is loading
$("#favicon").attr("href","/jw/images/favicon_my.ico");
 
$(document).ready(function() {
    // Set the Favicon after page load, in case the above doesn't set it properly
    $("head").append('<link rel="shortcut icon" href="/jw/images/favicon_my.ico"/>');
    // This might be required as well in some browsers
    $('link[rel="shortcut icon"]').attr('href','/jw/images/favicon_my.ico');
});

Credit: Solnet Solutions