Add authentication for private nuget feed in ARM template - azure

Question

The ARM template requirements for importing/applying a site extension nuget package is clear, but requires a public feed. What method should be used with a private Azure DevOps artifact nuget feed that requires authentication?
Template snippet below works with public feed, but returns Invalid feed Uri when private.
{
"name": "[variables('webAppName')]",
"type": "Microsoft.Web/sites",
"kind": "app",
"location": "[resourceGroup().location]",
"apiVersion": "2015-08-01",
"dependsOn": [
"[resourceId('Microsoft.Web/serverfarms', variables('appServiceName'))]"
],
"tags": {},
"properties": {
"name": "[variables('webAppName')]",
"serverFarmId": "[resourceId('Microsoft.Web/serverfarms', variables('appServiceName'))]",
"siteConfig": {
"WindowsFxVersion": "[parameters('windowsFxVersion')]",
"ftpsState": "Disabled",
"phpVersion": "Off",
"use32BitWorkerProcess": false,
"http20Enabled": true,
"minTlsVersion": "1.2",
"defaultDocuments": [
"index.html"
]
},
"hostNames": [
"[concat('wa-', parameters('baseAppName'),'.azurewebsites.net')]"
],
"siteProperties": {
"metadata": null,
"properties": [{
"name": "LinuxFxVersion",
"value": null
},
{
"name": "WindowsFxVersion",
"value": "DOTNETCORE|2.2"
}
],
"appSettings": null,
"httpsOnly": true
},
"availabilityState": "Normal",
"sslCertificates": null,
"httpsOnly": true,
"csrs": [],
"cers": null,
"siteMode": null,
"enabledHostNames": [
"[concat('wa-', parameters('baseAppName'),'.azurewebsites.net')]",
"[concat('wa-', parameters('baseAppName'),'.scm.azurewebsites.net')]"
]
},
"resources": [{
"name": "appsettings",
"type": "config",
"apiVersion": "2015-08-01",
"dependsOn": [
"[concat('Microsoft.Web/sites/', variables('webAppName'))]"
],
"properties": {
"SCM_SITEEXTENSIONS_FEED_URL": "[PRIVATE NUGET FEED]"
}
},
{
"apiVersion": "2015-08-01",
"name": "[SITE EXTENSION NAME]",
"type": "siteextensions",
"dependsOn": [
"[resourceId('Microsoft.Web/Sites', variables('webAppName'))]",
"[concat(resourceId('Microsoft.Web/Sites', variables('webAppName')),'/config/appsettings')]"
],
"properties": {}
}
]
}

Answer 1

It's not possible to use a private endpoint in a template deployment at this time.