Frappe lms app button

I want to add a button to LMS Quiz form


frappe.ui.form.on("LMS Quiz", {
  refresh: function(frm) {
    frm.add_custom_button(__("Upload PDF"), function() {
      frappe.ui.file_manager.show({
        allow_multiple: false,
        
        on_success: function(file) {
          frm.set_value("pdf_file", file.file_url);
          frm.save()
            .then(() => {
              frappe.msgprint(__("PDF has been uploaded and saved."));
            });
        }
      });
    });
  }
});

i added this script as a client script but it doesnt show on the lms app it is visible in the desk app

Could you please verify whether the script has been correctly added to the LMS Quiz Doctype’s JavaScript file?