Unable to contact snap store with Raspberry Pi 3 Model B

Hello sir:
I am using Raspberry Pi 3 Model B and want to install kanagame from snap store but failed.
Install kanagame on Raspberry Pi guide: https://snapcraft.io/install/kanagame/raspbian
Hardware: Raspberry Pi 3 Model B
Linux system: ubuntu-core-18-arm64+raspi4.img from http://cdimage.ubuntu.com/ubuntu-core/18/stable/current/
It seemed that I can’t find any snaps in snap store. Does anyone konw why?@ogra.
Error log:

What is snap changes and snap debug connectivity?



What is the output from running snap tasks 3?



Are you using an https or http proxy?

I didn’t used proxy.
I tried to use my android phone as a WIFI hotspot but still got the same error.
I used the same network and used vmware player to run “ubuntu-16.04.6-desktop-amd64.iso” and can “snap install xxx.snap” successfully.