Using HL6528RD-2.8V over USB

HL6528RD-2.8V has USB support .But there are few configuration settings that need to be applied via AT commands .
1.So for the first time,will the module accept AT commands over USB(assuming no configuration changes have been done from default state) ?
2.The few configuration settings(like “AT+KSIOCFG=1”) that need to be applied ,where shall it be fired for the first time (ie over USB or UART).
3.Do we need to first set the configuration over UART then use USB or we can directly use it.