We have very strict CSP rules that we are following for our website content. Unfortunately the default operation for ctrl+u will create a style attribute on a span that is not allowed. I found the following chunk of code to remove the ctrl+u shortcut for TinyMCE. In Umbraco 10, where would I implement this so that the default umbraco editor would use it?

tinyMCE.init({
// Your options here
setup: function(editor) {
    editor.on("init", function(){
        editor.addShortcut("ctrl+u", "", "");
    });
} });

Thank you