Zabbix toner left value null

Hi, i have issue with showing toner left value from zabbix API. In Grafana Singlestat Metric i get null value.
JSON

{
“id”: 22,
“title”: “Panel Title”,
“span”: 12,
“type”: “singlestat”,
“targets”: [
{
“refId”: “A”,
“mode”: 0,
“group”: {
“filter”: “Printers”
},
“host”: {
“filter”: “printername”
},
“application”: {
“filter”: “”
},
“item”: {
“filter”: “Toner left 6D 61 67 65 6E 74 61 00”
},
“functions”: [],
“options”: {
“showDisabledItems”: false
}
}
],
“links”: [],
“datasource”: “work”,
“maxDataPoints”: 100,
“interval”: null,
“cacheTimeout”: null,
“format”: “percent”,
“prefix”: “”,
“postfix”: “”,
“nullText”: null,
“valueMaps”: [
{
“value”: “null”,
“op”: “=”,
“text”: “N/A”
}
],
“mappingTypes”: [
{
“name”: “value to text”,
“value”: 1
},
{
“name”: “range to text”,
“value”: 2
}
],
“rangeMaps”: [
{
“from”: “null”,
“to”: “null”,
“text”: “N/A”
}
],
“mappingType”: 1,
“nullPointMode”: “connected”,
“valueName”: “avg”,
“prefixFontSize”: “50%”,
“valueFontSize”: “80%”,
“postfixFontSize”: “50%”,
“thresholds”: “”,
“colorBackground”: false,
“colorValue”: false,
“colors”: [
“rgba(245, 54, 54, 0.9)”,
“rgba(237, 129, 40, 0.89)”,
“rgba(50, 172, 45, 0.97)”
],
“sparkline”: {
“show”: false,
“full”: false,
“lineColor”: “rgb(31, 120, 193)”,
“fillColor”: “rgba(31, 118, 189, 0.18)”
},
“gauge”: {
“show”: false,
“minValue”: 0,
“maxValue”: 100,
“thresholdMarkers”: true,
“thresholdLabels”: false
},
“tableColumn”: