@snjlscmi If you are willing it may add value for your IT partner to participate in this thread since the solution may require some technical questions and answers.
Network pxe booting requires the cooperation of several technologies. As Sebastian mentioned having a picture of the error will help set the context of where its broken. If you get no iPXE menu then that means the iPXE boot loader is not being sent to the target computer. In this case undionly.kpxe (for a bios computer) or ipxe.efi (for a uefi computer) is not being sent to the target computer. This information is typically sent via the dhcp process.