Amazon web services 从事件规则捕获数组键的特定值及其在输入转换器中的值

我创建了一个规则，用于捕获使用cloud trail创建Ec2实例的用户。我收到了以下基于云跟踪事件的json

                    "rootDeviceType": "",
                    "rootDeviceName": "",
                    "blockDeviceMapping": {},
                    "virtualizationType": "",
                    "hypervisor": "",
                    "tagSet": {
                        "items": [
                            {
                                "key": "abc",
                                "value": "abc123"
                            },
                            {
                                "key": "pqr",
                                "value": "pqr123"
                            },
                            {
                                "key": "lkp",
                                "value": "lkp123"
                            },
                            {
                                "key": "yui",
                                "value": "yui111"
                            },
                            {
                                "key": "terra",
                                "value": "terra123"
                            }
                           
                        ]
                    },
                    "clientToken": "",
                    "groupSet": {
                        "items": [
                            {
                                "groupId": "",
                                "groupName": ""
                            }
                        ]
                    }

我想捕获key=“lkp”的值，但key lkp并非每次都出现在索引2处。我想查找key=lkp，并在SNS主题的输入转换器中捕获它的值

“资源名称”：“$.detail.tagSet.items[2][value]”