How to create a quote based on a subform list of a custom module

How to create a quote based on a subform list of a custom module

I created a subform list for my custom module.
Please tell me how to create a quote by passing it to the item list of the quote based on the subform list in a custom function.

The custom module JSON is as follows.
  1. {
  2.   "Owner": {
  3.     "name": "USER NAME",
  4.     "id": "0000000000000000000"
  5.   },
  6.   "$currency_symbol": "¥",
  7.   "Last_Activity_Time": "2019-03-23T22:04:14+09:00",
  8.   "Name": "1001",
  9.   "$process_flow": false,
  10.   "Currency": "JPY",
  11.   "id": "0002746000000239300",
  12.   "$approved": true,
  13.   "$approval": {
  14.     "delegate": false,
  15.     "approve": false,
  16.     "reject": false,
  17.     "resubmit": false
  18.   },
  19.   "Modified_Time": "2019-03-23T22:04:14+09:00",
  20.   "Created_Time": "2019-03-21T07:56:55+09:00",
  21.   "$editable": true,
  22.   "field10": 48800,
  23.   "field": {
  24.     "name": "株式会社サンプルカンパニー",
  25.     "id": "3872000000000216000"
  26.   },
  27.   "Tag": [],
  28.   "field3": [
  29.     {
  30.       "$approval": {
  31.         "delegate": false,
  32.         "approve": false,
  33.         "reject": false,
  34.         "resubmit": false
  35.       },
  36.       "$currency_symbol": "¥",
  37.       "Parent_Id": {
  38.         "name": "1001",
  39.         "id": "0002746000000239300"
  40.       },
  41.       "$editable": true,
  42.       "field1": 200000,
  43.       "field": {
  44.         "name": "PC # Example Laptop PC",
  45.         "id": "3872746000000227048"
  46.       },
  47.       "$process_flow": false,
  48.       "field7": 1000000,
  49.       "field6": 500000,
  50.       "id": "3872746000000239391",
  51.       "field3": 100000,
  52.       "field2": 5,
  53.       "$approved": true,
  54.       "field5": 500000,
  55.       "field4": 50
  56.     },
  57.     {
  58.       "$approval": {
  59.         "delegate": false,
  60.         "approve": false,
  61.         "reject": false,
  62.         "resubmit": false
  63.       },
  64.       "$currency_symbol": "¥",
  65.       "Parent_Id": {
  66.         "name": "1001",
  67.         "id": "0002746000000239300"
  68.       },
  69.       "$editable": true,
  70.       "field1": 300000,
  71.       "field": {
  72.         "name": "PC # Example Laptop PC",
  73.         "id": "3872746000000227048"
  74.       },
  75.       "$process_flow": false,
  76.       "field7": 1500000,
  77.       "field6": 1000000,
  78.       "id": "3872746000000239393",
  79.       "field3": 100000,
  80.       "field2": 5,
  81.       "$approved": true,
  82.       "field5": 500000,
  83.       "field4": 66.67
  84.     },
  85.     {
  86.       "$approval": {
  87.         "delegate": false,
  88.         "approve": false,
  89.         "reject": false,
  90.         "resubmit": false
  91.       },
  92.       "$currency_symbol": "¥",
  93.       "Parent_Id": {
  94.         "name": "1001",
  95.         "id": "0002746000000239300"
  96.       },
  97.       "$editable": true,
  98.       "field1": 15000,
  99.       "field": {
  100.         "name": "ITEM B",
  101.         "id": "3872746000000241031"
  102.       },
  103.       "$process_flow": false,
  104.       "field7": 90000,
  105.       "field6": 90000,
  106.       "id": "3872746000000241037",
  107.       "field3": null,
  108.       "field2": 6,
  109.       "$approved": true,
  110.       "field5": 0,
  111.       "field4": 100
  112.     },
  113.     {
  114.       "$approval": {
  115.         "delegate": false,
  116.         "approve": false,
  117.         "reject": false,
  118.         "resubmit": false
  119.       },
  120.       "$currency_symbol": "¥",
  121.       "Parent_Id": {
  122.         "name": "1001",
  123.         "id": "0002746000000239300"
  124.       },
  125.       "$editable": true,
  126.       "field1": 15000,
  127.       "field": {
  128.         "name": "ITEM B",
  129.         "id": "3872746000000241031"
  130.       },
  131.       "$process_flow": false,
  132.       "field7": 90000,
  133.       "field6": 90000,
  134.       "id": "3872746000000241057",
  135.       "field3": null,
  136.       "field2": 6,
  137.       "$approved": true,
  138.       "field5": 0,
  139.       "field4": 100
  140.     }
  141.   ],
  142. }