From a quick look (I don't know about this device in particular) it seems like it supports UEFI and therefore generic ARM64 UEFI target applies.
https://github.com/armbian/build/blob/main/config/boards/thinkpad-x13s.wip
This happened several times over the past years across almost all SoCs. Personally I discovered this first on the OPi1+ with H6 SoC and vendor images. Now I notice this on RK3588 when using 5.10.160 (rk4.1 branch and up) kernel...
Claims. But that's it. Those are made and provided by 3rd party. Armbian cannot and will not provide support for such.
https://docs.armbian.com/User-Guide_Getting-Started/#how-to-check-download-authenticity
You can always go ahead and use the build framework to build a kernel package or whole image with kernel configuration customized and stuff added you need: https://github.com/armbian/build
Maybe using the script provided here to fix missing libraries helps: https://blog.iancolwell.ca/steamlink-aarch64
Just ignore all the other stuff related to RPi only