Does the Rootable Kernel/ TWRP 3 – E6683 by Moonbutt74 work with Locked BL?

I reference the thread here
[Rootable Kernel/ TWRP 3 – E6853/E6883 Marshsmellow ] [32.1.A.1.163] AU]
Does this work with a Locked bootloader?

or is there a way to backup my DRM keys for the device before I root?

Thank You very much in advance for answering my question