AFAIK you can right below powershell query to leverage ultra disks, you need to determine which availability zone you are in. Not every region supports every VM size with ultra disks. To determine if your region, zone, and VM size support ultra disks, run either of the following commands, make sure to replace the region, vmSize, and subscription values first:
CLI:
$region = "southeastasia"
$vmSize = "Standard_E64s_v3"
(Get-AzComputeResourceSku | where {$_.Locations.Contains($region) -and ($_.Name -eq $vmSize) -and $_.LocationInfo[0].ZoneDetails.Count -gt 0})[0].LocationInfo[0].ZoneDetails
CLI:
$subscription = "<yourSubID>"
$region = "<yourLocation>, example value is southeastasia"
$vmSize = "<yourVMSize>, example value is Standard_E64s_v3"
az vm list-skus --resource-type virtualMachines --location $region --query "[?name=='$vmSize'].locationInfo[0].zoneDetails[0].Name" --subscription $subscription
I haven't tried it but you can try using api like below:
GET https://management.azure.com/subscriptions/{subscriptionId}/providers/Microsoft.Compute/locations/{location}/publishers/{publisherName}/artifacttypes/vmimage/offers/{offer}/skus?api-version=2019-03-01
and write query like below:
--query "[?name=='$vmSize'].locationInfo[0].zoneDetails[0].Name" --subscription $subscription
Try and see if it helps, feel free to tag me in your conversation.