MX740c esxi auto deploy in stateless mode, secure boot fails

Hello,

we use auto deploy in stateless mode to deploy our esxi servers. using uefi wihtout secure mode works fine, but we would like to activate booting with secure mode, but only get following error message:

UEFI0073: Unable to boot PXE device 1: nic in mezzanine 1a port 1 Partition 1 because of the secure boot policy.

how and where do I have to change the settings for this to work?

cheers

chris