How to avoid "This Size is not available in zone. . ."

Big thanks samy_vanderspikken for your proposal. Need to play with them,

But as you said:

"Also it could be that some VM sizes are unavailable as there is currently high demand for VMs in certain regions"

I was not able to understand how this could be hapen:

# Set the Context to one of my subscription:
PS C:\> set-azcontext -SubscriptionName mySub01

# Check the status:
PS C:\> Get-AzComputeResourceSku -Location "westeurope" | Where-Object { $_.name -EQ "Standard_D4ls_v5" }

ResourceType                Name   Location     Zones RestrictionInfo
------------                ----   --------     ----- ---------------
virtualMachines Standard_D4ls_v5 westeurope {3, 2, 1} type: Zone, locations: westeurope, zones: 1


# Set the Context to one of my subscription:
PS C:\> set-azcontext -SubscriptionName mySub02

# Check the status:
PS C:\> Get-AzComputeResourceSku -Location "westeurope" | Where-Object { $_.name -EQ "Standard_D4ls_v5" }

ResourceType                Name   Location     Zones RestrictionInfo
------------                ----   --------     ----- ---------------
virtualMachines Standard_D4ls_v5 westeurope {1, 2, 3} type: Zone, locations: westeurope, zones: 3

As you see, by changing only the subscription that affects to the availability:

RestrictionInfo: Zones: 1

RestrictionInfo: Zones: 3

I though to ask this from Microsoft as well, but thought to ask here if there is something which I do not know.