You can find the Intel UART driver below which you will find in the Asus ZenBook 14 UX431FN. This is another product which uses the Whiskey Lake hardware from Intel. The UART controller is used in many other products such as the ASUS ZenBook 14 UX431FN UART as well as the ASUS ZenBook 14 UX431FA UART. These Whiskey Lake UART drivers are all the same as the hardware used by Asus is mainly all the same.
ASUS ZenBook 14 UX431FN Intel UART Driver
The ASUS ZenBook 14 UX431FN is a well known notebook and you can use the same UART driver as with many others as the hardware is the same being an Intel UART controller which is very common in all their products. The ASUS ZenBook 14 UX431FN is using the same Whiskey Lake which others are using. You can download the file and then extract the files to a directory. The UART driver will be in the directory.
Also check to see if you can install the Windows 10 64 bit system by doing a right click on the inf file and then click on install. You can also simply click on the install file or use the Windows device manager to install the driver from there for your UART. There may be an error in the device manager and you can install the driver from there.