React to user follow with the Twitch API?

EventSub will send a noticitaion like this:

See Channel Follow Webhook Notification Example on the link I linked:

{
    "subscription": {
        "id": "f1c2a387-161a-49f9-a165-0f21d7a4e1c4",
        "type": "channel.follow",
        "version": "1",
        "status": "enabled",
        "cost": 0,
        "condition": {
           "broadcaster_user_id": "1337"
        },
         "transport": {
            "method": "webhook",
            "callback": "https://example.com/webhooks/callback"
        },
        "created_at": "2019-11-16T10:11:12.123Z"
    },
    "event": {
        "user_id": "1234",
        "user_login": "cool_user",
        "user_name": "Cool_User",
        "broadcaster_user_id": "1337",
        "broadcaster_user_login": "cooler_user",
        "broadcaster_user_name": "Cooler_User",
        "followed_at": "2020-07-15T18:16:11.17106713Z"
    }
}

The user that followed is this section of that JSON blob.

        "user_id": "1234",
        "user_login": "cool_user",
        "user_name": "Cool_User",