l5p ecm

I just received a new ecm for my truck. 2018 2500hd. I want to send it to hp tuners for the unlock upgrade program. My main question is since the ecm i have has not been programed to my truck yet can they still unlock it or do i need to have it reflashed to the truck first before i send it to them ?

Thanks for the help

They can unlock it, what you'll need to do when you install it is to run the ECM replacement in VCM Scanner, then swap em, then run it again to load your EMC data into the new one, the go in and turn off VATS and take it to the dealer to get the keys re-programmed.