Recently I created advanced map using Sentinel-2. It shows fire on specific past date but It is not publicly access currently it is auto popup login information so is it possible to view without login?
webmap id: 79e1f429538b41698d97fc819dc412fe
Make sure all the items that you are trying to show are not a premium content of some kind. If all the items are your own, I would check the sharing setting to make sure everything is set for public.
I checked your services that the app is pulling and those don't seem to be a problem. Have you enabled subscriber content to be used in Web apps/Story maps?
If it's still prompting a log in.. Can you try the following workaround?