What Fusion "edition" are both you and your user using? Fusion 13 Pro or Player?
Edited:
Fusion Player does not have the "Power on to Firmware" menu option. Fusion Pro does have that menu option.
If they're running Player, then they need to click in the VM and press fn-F2 during initial VM startup to get to the firmware/BIOS menu.
By default, the window to do this is very short and can be tricky to time it right. See KB article https://kb.vmware.com/s/article/1004129 for info on how to get around this (there are two methods).