Linux/AM3358: Could find the kernel header files for Makefile

Part Number: AM3358

Tool/software: Linux

I am using AM3358 Beaglebone Black Board for software development and trying to wirte kernel module code.  However, the original

 image didn't come with the kernel header file and Makefile keeps shows error.  Is there any one could help to pointing me to the right location where I could download the correct kernel header file?

The Linux distrib image I am using is Ubuntu 18.04

uname -a

Linux arm 4.14.108-ti-r104 #1 SMP PREEMPT Tue Apr 9 18:45:06 UTC 2019 armv7l arm
v7l armv7l GNU/Linux

Thanks ahead.