location redirect to "sms:123454" does not work on page load

Following is the code I have got for location redirect to SMS app when the user is on a mobile browser-

window.onload = function() {
    window.location ="sms:12345?body=" + encodeURIComponent("TEST");
}

This code works perfectly on JS fiddle when running on a mobile JS Fiddle link -https://jsfiddle.net/netstarter/rwqyp2tn/1/

from location redirect to "sms:123454" does not work on page load