Vega-lite - > It's possible to switch (on/off) stack in barchart for example using checkbox

[Myrec77]

Hi,
i make simple barchart with count of Errors. I would like to need the barchart with two options:
"stacked" i see total count of errors in months. And "non-stacked" if i choose in legend one error -> i see how go this Errors through Monts. Is there some option to use for example checkbox - which can change stack option? i Try it via param {"name":"stack", "value":true} And put this parametr to "stack" option - but in vega editor i received Error (Incorrect type. Expected "string".).

Thanks a lot

My code:
`{
"$schema": "https://vega.github.io/schema/vega-lite/v5.json",
"width": 200,
"height": 400,
"title": "Count errors [month]",
"params": [{
"name": "Chyba",
"select": {
"type": "point",
"fields": ["chyba"]
},
"bind": "legend"
},
{
"name": "stack",
"value":"zero"
}
],
"data": {
"values": [{"chyba":"err_1","cas":"2022/08","pocet":50},{"chyba":"err_2","cas":"2022/08","pocet":23},{"chyba":"err_3","cas":"2022/08","pocet":17},{"chyba":"err_1","cas":"2022/09","pocet":16},{"chyba":"err_2","cas":"2022/09","pocet":45},{"chyba":"err_3","cas":"2022/09","pocet":37},{"chyba":"err_1","cas":"2022/10","pocet":17},{"chyba":"err_2","cas":"2022/10","pocet":1},{"chyba":"err_3","cas":"2022/10","pocet":1},{"chyba":"err_1","cas":"2022/11","pocet":6},{"chyba":"err_2","cas":"2022/11","pocet":12},{"chyba":"err_3","cas":"2022/11","pocet":2}]
},
"mark": {
"type": "bar",
"tooltip": true,
"point":{
"size":100
}

},
"encoding": {
    "x": {
        "title": null,
        "field": "cas",
        "timeUnit":"yearmonth",
        "type": "ordinal",
        "axis": {
            "titleFontSize": 15,
            "labelAngle": 0,
            "labelFontSize": 12,
            "labelFontWeight": 600
        }
    },
    "y": {
        "field": "pocet",
        "aggregate":"sum",
        "type": "quantitative",
        "stack":false,
        

        "axis": {
            "labelPadding":20,
            "title": "Count Errors",
            "ticks": false,
            "titleFontSize": 15,
            "labelFontSize": 12,
            "labelFontWeight": 600
        }
    },
    "color": {
        "field": "chyba",
        "type": "nominal",
        "legend": {
            "labelFontSize": 16,
            "labelLimit": 600,
            "labelOffset": 10,
            "title": "Type of error",
            "titleFontSize": 16
        }
    },
    "opacity": {
        "condition": { "param": "Chyba", "value": 1 },
        "value": 0
    }
}

}`