You have an Azure subscription that contains an Azure Compute Gallery named Gallery1 and a virtual machine named Template1. Template1 has custom apps and settings configured.
You plan to deploy Azure Virtual Desktop session hosts by using a custom virtual machine image. The solution must meet the following requirements:
• The custom image must be stored in Gallery1.
• The custom image must be based on Template1.
• All new session hosts must have unique computer names and identifiers.
You need to create the custom image.
What should you do in the Azure portal?