Send & Get Data From USB HID RL Library

Hi .
I Using LPC1768 Microprocessor and R-Arm Library in HID Class
my Question is In Rl-arm Library How to Get & Send data ?

i mean what the syntax or Function to use this job ?

Second , What the Endpoint Function ?

last is , how to use interrupt in Receive Data in HID Class ?

Please Help with the example And Source Code

thanks Engineers