Open BigBroActivator and select the "Boot Ramdisk" option. The tool will send the exploit to your device.
How to Bypass Passcode and Activation Lock with BigBroActivator-Ramdisk v2 BigBroActivator-Ramdisk v2 Passcode
Since it boots into a custom Ramdisk, you don't need to pre-jailbreak with tools like Palera1n or Checkra1n. Step-by-Step: Using the Passcode Bypass Open BigBroActivator and select the "Boot Ramdisk" option