How to get Sender IP using Microsoft Graph API?

The Graph API response looks something similar to the following and the Authentication-Results gives me the relevant origin Sender IP -

{
    "@odata.context":"<some-value>",
    "@odata.etag":"<some-value>",
    "id":"<some-value>",
    "internetMessageHeaders":[
        {
            "name":"MIME-Version",
            "value":"1.0"
        },
        {
            "name":"Content-Type",
            "value":"multipart/report"
        },
        {
            "name":"x-custom-header-group-name",
            "value":"Washington"
        },
        {
            "name":"x-custom-header-group-id",
            "value":"WA001"
        },
        {
            "name":"Receiver",
            "value":"<some-ip>"
        },
        {
            "name":"Receiver",
            "value":"<some-ip>"
        },
        {
            "name":"Authentication-Results",
            "value":"spf=pass (sender ip is <some-ip>)...,"       
        }
    ]
}

Now, all you need is a regex to extract -

1. Get the value present in Authentication-Results
2. Use the Regex - \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3} to extract IP, use the first occurence of the match with regex.