How do I convert JSON from the old structure to the new structure using the function node?

[Roket]

Hey!
How do I convert JSON from the old structure to the new structure using the function node?

Old structure:

"meta_input":{
	"first_custom_key": "first custom value",
	"second_custom_key": "second custom value"
}

New structure:

"manage_meta_data":{
	"update_post_meta":[
		{
		"meta_key": "first_custom_key",
		"meta_value": "first custom value"
		},
		{
		"meta_key": "second_custom_key",
		"meta_value": "second custom value"
		}
]
}

[RicardoE105]

Check the example below:

{
  "nodes": [
    {
      "parameters": {},
      "name": "Start",
      "type": "n8n-nodes-base.start",
      "typeVersion": 1,
      "position": [
        250,
        300
      ]
    },
    {
      "parameters": {
        "functionCode": "return [\n  {\n    json: {\n      \"meta_input\":{\n\t\"first_custom_key\": \"first custom value\",\n\t\"second_custom_key\": \"second custom value\"\n}\n    }\n  }\n]"
      },
      "name": "Function",
      "type": "n8n-nodes-base.function",
      "typeVersion": 1,
      "position": [
        450,
        300
      ]
    },
    {
      "parameters": {
        "functionCode": "const data = items[0].json.meta_input  \n\nconst postMeta = [];\n\nfor (const key of Object.keys(data)) {\n  postMeta.push({\n    meta_key: key,\n    meta_value: data[key]\n  })\n}\n\nreturn [\n  {\n    json: {\n      manage_meta_data: {\n        update_post_meta: postMeta\n      }\n    }\n  }\n]"
      },
      "name": "Function1",
      "type": "n8n-nodes-base.function",
      "typeVersion": 1,
      "position": [
        650,
        300
      ]
    }
  ],
  "connections": {
    "Start": {
      "main": [
        [
          {
            "node": "Function",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Function": {
      "main": [
        [
          {
            "node": "Function1",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  }
}

[Roket]

Ricardo, thank you very much!