aks-modify.json

{
    "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
    "contentVersion": "1.0.0.0",
    "parameters": {
        "location": {
            "type": "string",
            "metadata": {
                "description": "The location for all the resources."
            }
        },
        "aksName": {
            "type": "string",
            "metadata": {
                "description": "The name of the AKS Cluster."
            }
        },
        "kubernetesVersion": {
            "type": "string",
            "metadata": {
                "description": "The version of Kubernetes."
            }
        }
    },
    "resources": [
        {
            "type": "Microsoft.ContainerService/managedClusters",
            "apiVersion": "2020-11-01",
            "name": "[parameters('aksName')]",
            "location": "[parameters('location')]",
            "properties": {
                "kubernetesVersion": "[parameters('kubernetesVersion')]"
            }
        }
    ]
}