Error 400 when I try to login in to the community

Hello, I write this topic because I have a problem with the login page. Now I have been logged-in, but when I try to log-in with a new browser or device I have the “redirect_uri_mismatch” error, and the page says: “The redirect URI in the request,, does not match the ones authorized for the OAuth client…”, On the same day I managed to access it without problems and after some times I could not access it since then I can no longer access. Please can someone help me?