Unable to load an device tree overlay in ubuntu

[RossWilliamson]

I'm trying to load a compiled device tree overlay. If I understand it correctly I need to cat the binary file into /sys/kernel/config/device-tree/overlays/node but the only directory inside config is pci_ep. It looks as if I am running kernel 6.14.0-28-generic. I've checked and the following is set. I did not recompile my own kernel. Any help appreciated.

CONFIG_OF_OVERLAY=y
CONFIG_CONFIGFS_FS=y