Zend certified PHP/Magento developer

how i get the kernel header for my server?

i have a question about my odroid xu4 with xubuntu. after i have done an dist-update my wireguard wont work. after a little research came out that i havent install the kernel-headers for the version. my uname-a is Linux odroid 5.4.167-238 #1 SMP PREEMPT Tue Jan 25 07:31:53 EST 2022 armv7l armv7l armv7l GNU/Linux. i tried apt install linux-headers-$(uname -r) an i entered the version manuelly but linux cant find it. i also tried to add the ubuntu backports to the /etc/apt/source.list but it also worked not. even the apt search didnt near bring the correct version. i googled for some repo links to add to the source.list but i got like nothing so i tried this way.

thanks for any help ЁЯЩВ