DSCResources/MSFT_SPOSearchResultSource/settings.json

{
    "resourceName": "SPOSearchResultSource",
    "description": "",
    "permissions": [
        {
            "read": [
                {
                    "name": "Sites.FullControl.All"
                }
            ],
            "update": [
                {
                    "name": "Sites.FullControl.All"
                }
            ]
        }
    ]
}