Here are some articles that may answer your question:
Create a VM from a VHD by using the Azure portal
https://learn.microsoft.com/en-us/azure/virtual-machines/windows/create-vm-specialized-portal
Create a Windows VM from a specialized disk by using PowerShell
https://learn.microsoft.com/en-us/azure/virtual-machines/windows/create-vm-specialized
If you need it, there is a quick module on this as well on the Microsoft Learn site:
Deploy Azure virtual machines from VHD templates
https://learn.microsoft.com/en-us/learn/modules/deploy-vms-from-vhd-templates/
Hope this helps!
Edward