I feel really really dumb.. how to?

Hello, I have this code, which works very well by jsut adding it to the functions php.. except in this case I am now uing a system (oxygenapp) that does not rely on a theme thus no child-theme and functions.php

How can I use lour plugin to make this work ?!?
I need this toi be global, not shortcode based.
I don’t imagine qnyone will answer but then again .. who knows..

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function jquery_parallax() {

?>
<script language=”JavaScript” type=”text/javascript”>

;(function($) {

‘use strict’

var testMobile;
var isMobile = {
Android: function() {
return navigator.userAgent.match(/Android/i);
},
BlackBerry: function() {
return navigator.userAgent.match(/BlackBerry/i);
},
iOS: function() {
return navigator.userAgent.match(/iPhone|iPad|iPod/i);
},
Opera: function() {
return navigator.userAgent.match(/Opera Mini/i);
},
Windows: function() {
return navigator.userAgent.match(/IEMobile/i);
},
any: function() {
return (isMobile.Android() || isMobile.BlackBerry() || isMobile.iOS() || isMobile.Opera() || isMobile.Windows());
}
};

var parallax = function() {
testMobile = isMobile.any();
if (testMobile == null) {
$(“.parallax”).parallax(“50%”, 0.3);
}
};

// Dom Ready
$(function() {
parallax();
});
})(jQuery);

/*
jQuery Parallax 1.1.3
Author: Ian Lunn
Plugin URL: https://www.ianlunn.co.uk/plugins/jquery-parallax/

Dual licensed under the MIT and GPL licenses:
https://www.opensource.org/licenses/mit-license.php
https://www.gnu.org/licenses/gpl.html
*/
!function(n){var t=n(window),e=t.height();t.resize(function(){e=t.height()}),n.fn.parallax=function(o,r,i){function u(){var i=t.scrollTop();l.each(function(t,u){var l=n(u),f=l.offset().top,s=a(l);i>f+s||f>i+e||l.css(“backgroundPosition”,o+” “+Math.round((l.data(“firstTop”)-i)*r)+”px”)})}var a,l=n(this);l.each(function(t,e){$element=n(e),$element.data(“firstTop”,$element.offset().top)}),a=i?function(n){return n.outerHeight(!0)}:function(n){return n.height()},(arguments.length<1||null===o)&&(o=”50%”),(arguments.length<2||null===r)&&(r=.1),(arguments.length<3||null===i)&&(i=!0),t.bind(“scroll”,u).resize(u),u()}}(jQuery);

</script>
<?php

}

if (!(is_admin())) {
wp_enqueue_script(‘jquery’);
add_action(‘wp_head’, ‘jquery_parallax’);
}