Posting this simple solution here. Seen a lot of requests for the OTP Email to be sent out automatically when users are logging in to ServiceNow

UI Script - AutoEmailOTP

addLateLoadEvent(function(){
    setTimeout(function(){
        var windowLoc = top.window.location;
        console.log('validating window..,');
        if(windowLoc.href.includes("validate_multifactor_auth_code")){
            console.log('window validated, triggering onClick...');
            multifactorSendOneTimePassword();
        }
    }, 1000); //1 second delay
});

Notes:

- Feel free to remove the console.log() lines

- The 1 second delay is necessary to allow window.location.href to change from "navpage.do" to "validate_multifactor_auth_code.do". This may need to increase if some users have particularly slow browsers/PCs.