See the explanation below.
You need to configure an option in the Advanced Access Policy of the key vault. 1. In the Azure portal, type Azure Key Vault in the search box, select Azure Key Vault from the search results then select the key vault named KV11597200. Alternatively, browse to Azure Key Vault in the left navigation pane. 2. In the properties of the key vault, click on Advanced Access Policies. 3. Tick the checkbox labelled Enable access to Azure Resource Manager for template deployment. 4. Click Save to save the changes.