Hi Gabriel,
I just checked the config for your legacy kernel. CAN is not available, nor is the driver. I suspect that you will need to use current kernel for this driver.
You can search these forums to see if there are issues with the current kernel and if there are perhaps ways to get it working.
It may be that issues with the new kernel have not been resolved for your board, or you may find that someone has got it working.
If you want to learn and get involved then the Armbian build system is an ideal platform for you to develop solutions, providing an easy way to apply patches and stream improvements into the build via Github pull requests.
I don't have your board, so won't be of much help.