[PVE-User] Kernel documentation for building modules

[Angel Rengifo Cancino]

Hello guys:

I'm running Proxmox VE 7 with kernel 5.11.22-4-pve. Everytime I try to
build a module or even when running "make oldconfig" I get an error message
like:

 Kconfig:36: can't open file "Documentation/Kconfig"

I tried searching different Proxmox packages but I couldn't find one that
contains that directory and file.

Has anyone been able to build modules on Proxmox 7?