It looks the problem of your browser or server.
I request you to once clear the cache of your browser and the try to access back-office URL again.
I also request you to once check the admin folder (in your QloApps directory structure find the folder which name starts with admin) name in your directory structure.
If admin folder name has changed the try to access that folder from URL "localhost/hrms/admin_folder_name" .
I also request you to once visit https://www.ionos.com/digitalguide/hosting/technical-matters/err-connection-reset/ and try to resolve issues which may occur this issue on your system.
Please try once with the above solution.
If issue persists then please let us know.