public setItemIntoRoamingSettings<T>(name: string, item: T) {
  Office.context.roamingSettings.set(name, item);
  Office.context.roamingSettings.saveAsync(function(asyncResult) {
    console.log(asyncResult);
  });

{
 error:
  {
    code: 9019,
    message: "Permission Denied",
    name:  "GenericSettingsError"
   },
 status: "failed"
}