Title! Here's more info https://superuser.com/questions/1821686/install-specific-linux-kernel-headers
#Install specific Linux kernel headers
3 messages · Page 1 of 1 (latest)
You likely missed installing the linux-headers packages from https://kernel.ubuntu.com/mainline/v6.6.6/
You need the devel headers for Linux yes, this is usual in a package called Linux-headers or Linux-headers-devel