Download iOS 13.1.3 (17A878) for iPhone XR

You will have to note that you can only restore signed IPSW firmware files using iTunes or 3utools.

Firmware Identifier	iPhone11,8
iOS Version	13.1.3
Release Date	2019-10-15
Update Date	2019-10-10
Sha1sum	a751d03cb4dd324bf702d618439d049a8c940efb
Sha256sum	8e81b64f0bd7dd5d4d71ebb2ea372d48be2d2c6038136ea29b9907c9046fafb7
md5sum	3d4581b898ccb06fdf492a3bbf087cc5
Size	3.77 GB
FileName	iPhone11,8_13.1.3_17A878_Restore.ipsw
Status

It should be noted that these are the official release notes for the from Apple

iOS 13.1.3 includes bug fixes and improvements for your iPhone. This update:

Addresses an issue that could prevent a device from ringing or vibrating for an incoming call
Fixes an issue that may prevent opening a meeting invite in Mail
Resolves an issue where data in the Health app may not display correctly after daylight savings time adjusts
Fixes an issue where Voice Memos recordings may not download after restoring from iCloud Backup
Addresses an issue where apps might fail to download when restoring from iCloud Backup
Fixes an issue that can prevent Apple Watch from pairing successfully
Resolves an issue where notifications may not be received on Apple Watch
Fixes an issue where Bluetooth may disconnect on certain vehicles
Improves connection reliability of Bluetooth hearing aids and headsets
Addresses launch performance for apps that use Game Center

For information on the security content of Apple software updates, please visit this website: