STM32F103 USB HID

I am trying to connect my board to my computer with no success.

Here's what I've tried; I tried "STM32 FS Device Lib". It includes a sample project named Custom HID. But it also uses some LEDs, some EXTI and a pin named USB_DISCONNECT. I ported the code, removed the USB_DISCONNECT part and LEDs. When I call USB_init (), nothing happens. The device was not found on the computer.

There is no need to set up custom endpoints, descriptor or anything else. Just communication for personal use. I just want call functions, i.e. USB_read () and USB_write ().

Is there some simple library or example project I can use?