URL in incognito mode reply with Not Found The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.
but the same URL can access in normal mode in three browsers chrome,firefox and edge.
what is the reason can make this issue and how can i resolve it?
Assuming you have multiple database in your Odoo instance, on incognito mode when you are tying to load the url, as the controller isn't bound to any DB in the session yet, you are getting that error. It's working on normal browser because on that session you have a DB bound to it.