We are currently using Ubuntu Server 18.04 LTS for our self-hosted Azure VMs and looking into upgrading them to Ubuntu Server 20.04 LTS. We used the URN Canonical:UbuntuServer:18.04-LTS:latest to create our existing self-hosted Azure VMs.
This webpage link (https://az-vm-image.info/?cmd=--all+--publisher+Canonical) lists the URNs for the various Azure VM images that az vm image list --output table command would list from the Azure CLI.
If you collapse groups for that webpage, I would expect a Canonical - UbuntuServer - 20.04-LTS or Canonical:UbuntuServer:20.04-LTS:<version>to be at the end of that list but it isn't. I know the Azure VM image exist though because the marketplace has it: https://azuremarketplace.microsoft.com/en-us/marketplace/apps/canonical.0001-com-ubuntu-server-focal?tab=Overview
I'm new to this so I'm not sure how to get the URN out of that marketplace link or which is the correct URN at the az-vm-image link above to get UbuntuServer 20.04 LTS for our self-hosted Azure VMs.
For reference, I am using the Azure CLI command az vm create .. --image Canonical:UbuntuServer:18.04-LTS:latest .. to create our VMs. I tried Canonical:UbuntuServer:20.04-LTS:latest and the VM image doesn't exist.