Using a CirrOS/TinyCore image in MAAS

Hi, I have MAAS (version: 2.4.2) installed in a Virtual Machine Manager VM and I have one PC Engines APU2C4 node commission and ready to be deployed.

What I want is to deploy a small image like CirrOS or TinyCore to test if my setup is well configured.
But when I tried to add these custom images I got an error saying that the file it’s not a .tgz file.