where properties.emailReceivers has_cs "DevSecOps@pato.com" is theoretically not 100% safe ("DevSecOps@pato.com" might appear in fields other than "emailAddress"), but in your case it might be enough and if you have a large data set it will also be fast.
If you need a 100% guarantee, then also add the following:
where dynamic_to_json(properties.emailReceivers) matches regex '"emailAddress":"DevSecOps@pato.com"'
It's not pretty, but Azure Resource Graph uses just a subset of the KQL supported by Azure Data Explorer.

let resources = datatable(id:string, name:string, resourceGroup:string, subscriptionId:string, location:string, type:string, properties:dynamic)
[
    "my_id"
   ,"my_name"
   ,"my_resourceGroup"
   ,"my_subscriptionId"
   ,"my_location"
   ,"microsoft.insights/actiongroups"
   ,dynamic
    (
        {
            "enabled": true,
            "automationRunbookReceivers": [],
            "azureFunctionReceivers": [],
            "azureAppPushReceivers": [],
            "logicAppReceivers": [],
            "eventHubReceivers": [],
            "webhookReceivers": [],
            "armRoleReceivers": [],
            "emailReceivers": [
                {
                    "name": "TED",
                    "status": "Enabled",
                    "useCommonAlertSchema": true,
                    "emailAddress": "tedtechnicalengineeringdesign@pato.com"
                },
                {
                    "name": "SevenOfNine",
                    "status": "Enabled",
                    "useCommonAlertSchema": true,
                    "emailAddress": "sevenofnine@pato.com"
                },
                {
                    "name": "PEAT",
                    "status": "Enabled",
                    "useCommonAlertSchema": true,
                    "emailAddress": "DevSecOps@pato.com"
                }
            ],
            "voiceReceivers": [],
            "groupShortName": "eng-mon",
            "itsmReceivers": [],
            "smsReceivers": []
        }
    )
];
resources
| where type == "microsoft.insights/actiongroups"
| where properties.enabled == true
| where properties.emailReceivers has_cs "DevSecOps@pato.com"
| where dynamic_to_json(properties.emailReceivers) matches regex '"emailAddress":"DevSecOps@pato.com"'
| project id,name,resourceGroup,subscriptionId,properties,location
| order by tolower(name) asc

Fiddle

我找到了一种方法，使用关键字“包含”。
这样就不需要指定它应该在哪个插槽中找到它，它可以是[0]、[1]、[2]...[n]

resources
| where type == 'microsoft.insights/actiongroups'
| where properties["enabled"] in~ ('true')
| where properties['emailReceivers'] contains "DevSecOps@pato.com"
| project id,name,resourceGroup,subscriptionId,properties,location
| order by tolower(tostring(name)) asc