Error compiling blender

When I try to run make -j1 in blender I get the following error:

In file included from /home/kuser/Documents/School/blender-src/intern/audaspace/intern/AUD_PyInit.cpp:25:
/home/user/Documents/School/blender-src/intern/audaspace/intern/AUD_PyInit.h:29:12: fatal error: Python.h: No such file or directory
29 | # include “Python.h”
| ^~~~~~~~~~

Does anyone know how to solve this?

Hi, do you use prebuild libraries?
If not you are missing python 3.9 dev package.
It is much easier to use the libraries from Blender instead of building all yourself.
https://wiki.blender.org/wiki/Building_Blender/Linux/Ubuntu

Cheers, mib