{
  ...
  "resources": [
    {
      "apiVersion": "2015-08-01",
      "name": "[parameters('websiteName')]",
      "type": "Microsoft.Web/sites",
      "location": "[resourceGroup().location]",
      "properties": {
        "hostNameSslStates": [
          {
            "name": "[parameters('websiteCustomDomainName')]",
            "sslState": "SniEnabled",
            "thumbprint": "[parameters('certificateThumbprint')]",
            "toUpdate": true
          }
        ]
      }
    }
  ]
  ...
}