Use the Longan Nano as USB device on host computer

Is there some documentation on How to use the Longan Nano as USB device ?
Is it event possible ?
For example, is it possible to communicate with the HID interface ?

GD32VF103_Firmware_Library
There are some USBFS examples. And you can see the TRM of GD32VF103.The chapter 21 of GD32VF103 UserManual is usbfs.

Thanks, I will take a look.