How to expand the detailPanel in MatrixDynamic ?

Hello,

We have a Custom Matrix Dynamic question. We want to show the detailPanel expanded by default. Currently all detailPanel rows are collapsed.

I have added screenshots and json for this question to the attachment.

Please guide us to implement this.

JSON
{
    "type": "matrixdynamic",
    "name": "treatPlanObjectivesAndGoals",
    "state": "expanded",
    "title": "Treatment Plan Objectives and Goals",
    "hideNumber": true,
    "columns": [
        {
            "name": "index",
            "title": " ",
            "cellType": "expression",
            "width": "5%",
            "expression": "{rowIndex}"
        },
        {
            "name": "Goal Name",
            "cellType": "text",
            "minWidth": "300px"
        },
        {
            "name": "dueDate",
            "title": "Due Date",
            "cellType": "text",
            "minWidth": "300px",
            "inputType": "date"
        }
    ],
    "detailElements": [
        {
            "type": "dropdown",
            "name": "priority",
            "title": "Priority",
            "choices": [
                "High",
                "Medium",
                "Low"
            ]
        },
        {
            "type": "text",
            "name": "dateInitiated",
            "title": "Date Initiated",
            "defaultValueExpression": "getDate()",
            "inputType": "date"
        },
        {
            "type": "radiogroup",
            "name": "goalStatus",
            "title": "Goal Status",
            "hideNumber": true,
            "choicesByUrl": {
                "url": "[https://api.example.com/v1/api/goals](https://api.example.com/v1/api/goals)",
                "valueName": "name",
                "titleName": "name",
                "allowEmptyResponse": true
            }
        },
        {
            "type": "text",
            "name": "dateCompleted",
            "visibleIf": "{row.goalStatus} =='Completed'",
            "title": "Date Completed",
            "inputType": "date"
        },
        {
            "type": "matrixdynamic",
            "name": "objectives",
            "title": "Objective",
            "columns": [
                {
                    "name": "index",
                    "title": " ",
                    "cellType": "expression",
                    "width": "5%",
                    "expression": "{rowIndex}"
                },
                {
                    "name": "interventionSteps",
                    "title": "Intervention Steps",
                    "cellType": "comment",
                    "minWidth": "400px",
                    "rows": 11
                },
                {
                    "name": "stageofReadiness",
                    "title": "Stage of Readiness",
                    "cellType": "dropdown",
                    "choices": [
                        "Action",
                        "Preparation",
                        "Maintenance",
                        "Pre-contemplation",
                        "Contemplation"
                    ]
                },
                {
                    "name": "barriers",
                    "title": "Barriers",
                    "cellType": "comment",
                    "minWidth": "400px",
                    "rows": 11
                },
                {
                    "name": "outcome",
                    "title": "Outcome",
                    "cellType": "comment",
                    "minWidth": "400px",
                    "rows": 11
                },
                {
                    "name": "objectiveCompleted",
                    "title": "Objective Completed",
                    "cellType": "dropdown",
                    "choices": [
                        "Yes",
                        "No"
                    ]
                },
                {
                    "name": "objectiveCompletiondate",
                    "title": "Objective Completion Date",
                    "cellType": "text",
                    "minWidth": "400px",
                    "visibleIf": "{Intervention[0].objectiveCompleted} == 'Yes'",
                    "inputType": "date"
                }
            ],
            "choices": [
                1,
                2,
                3,
                4,
                5
            ],
            "allowRemoveRows": false,
            "rowCount": 1,
            "addRowText": "Add Intervention"
        }
    ],
    "detailPanelMode": "underRow",
    "rowCount": 1,
    "maxRowCount": 50,
    "addRowText": "Add Goal",
    "removeRowText": "Remove Goal",
    "detailPanelShowOnAdding": true
}

Thanks
Shobhit