The following may help if you are experiencing problems while trying to Add Azure Host.
Azure Stuck at Provisioning
If the VM selected has less than the minimum memory requirement then Provisioning will not complete.
Azure Provisioning Fails
If the VM selected has is NOT available in the selected Region then Provisioning will fail.
You can check availability from the Azure CLI with command:
az vm list-skus --location westus --size Standard_A --output table
where westus = Region and Standard_A = VM type