Try this

I stored your sample json in variable json

var json = {
  "meta": {
    "a2": 200,
    "ta": "dasd",
    "asdd": "asdda"
  },
  "data": {
    "items": [
      {
        "id": "",
        "number": "",
        "origin_info": {
          "ItemReceived": "2021-10-02 02:07:49",
          "phone": 123456789,
          "trackinfo": [
            {
              "StatusDescription": "what i need",
              "Details": "",
              "substatus": "ok"
            },
   
            {
              "StatusDescription": "what i need",
              "Details": "",
              "substatus": "ok"
            }
          ]
        },
        "destination_info": null,
        "lastEvent": "grgrgrgrgr",
        "lastUpdateTime": "mewmemew"
      }
    ]
  }
}

Accessed it like below

console.log(json.data.items[0].origin_info.trackinfo[0].StatusDescription);

Items is an array and we took array element 0.

trackinfo again is an array and we took array element 0.

We can change array index or loop through and get required values.

You have to iterate through your items and trackinfo to get to StatusDescription. Try this one.

const data =  {
  "meta": {
    "a2": 200,
    "ta": "dasd",
    "asdd": "asdda"
  },
  "data": {
    "items": [
      {
        "id": "",
        "number": "",
        "origin_info": {
          "ItemReceived": "2021-10-02 02:07:49",
          "phone": 123456789,
          "trackinfo": [
            {
              "StatusDescription": "what i need",
              "Details": "",
              "substatus": "ok"
            },
   
            {
              "StatusDescription": "what i need",
              "Details": "",
              "substatus": "ok"
            }
          ]
        },
        "destination_info": null,
        "lastEvent": "grgrgrgrgr",
        "lastUpdateTime": "mewmemew"
      }
    ]
  }
}

const items = data.data.items.map(item => item)
const trackinfo = items.map(item => item.origin_info.trackinfo).flat()
console.log(trackinfo)
const statusDescription = trackinfo.map(trackinfo => trackinfo.StatusDescription)

console.log(statusDescription)