you need to edit the config.plist file in an editor like PlistEditPro cause clover configurator will not allow you to add code only change preconfigured settings. You need to add these lines of code in your config.plist (courtesy of slice2009 and clover team for implementing this):
and make sure that you place it correctly-if it can be saved you have succeeded-(PlistEditPro will not save the file unless code is correctly entered). What this does is it removes system integrity protection (SIP) and allows third party kexts in S/L/E to load. The flag 0x67 disables the protection and can be re-enabled by changing to 0x00. After this rebuild kernel caches and reboot and if you did things correctly beta 3 will boot with full kext support.
I am assuming that you have already installed the beta and can boot into it? if not you will have to do this from a separate osx disk!