PFSense DHCP server and Vercot Serva's PXE

[pbnet]

Dear community,

I would need some help.
I have a PFSense 2.4.4 P3 box and I'm trying to configure PFSense's DHCP to also allow network boot (PXE) from a Vercot Serva server (https://www.vercot.com/~serva/an/WindowsPXE1.html)

I've followed the instructions on Serva's site, but still missing something, and since I never done this before, I thought I might ask you guys.

Here's what I did on the PFSense side:

The Serva's errors I get and how I configured it:

Any hint is greatly appreciated.

Thanks.
Andy