jp-postal/package.json

There are instructions to download, rebuild and obtain the latest data from official source

{
  "name": "jp-postal",
  "version": "4.0.1",
  "main": "index.cjs",
  "type": "module",
  "license": "MIT",
  "repository": "github:tranvansang/jp-postal",
  "keywords": [
    "japanese",
    "postal",
    "postal-code",
    "address",
    "yubinbango",
    "郵便番号",
    "〒",
    "住所",
    "日本住所"
  ],
  "author": "Sang <t@sang.jp>",
  "files": [
    "index.cjs",
    "index.mjs",
    "index.d.ts"
  ],
  "exports": {
    ".": {
      "require": "./index.cjs",
      "import": "./index.mjs",
      "types": "./index.d.ts"
    }
  },
  "scripts": {
    "rebuild": "npm i && npm run download && npm run unzip && npm run enc-convert && npm run js-convert && npm run build && npm run test",
    "download": "wget -O ken_all.zip http://www.post.japanpost.jp/zipcode/dl/kogaki/zip/ken_all.zip",
    "unzip": "unzip -o ken_all.zip",
    "enc-convert": "iconv -f sjis -t utf8 KEN_ALL.CSV > KEN_ALL-utf8.CSV",
    "js-convert": "node convert.mjs",
    "test": "node test.mjs",
    "build": "./build.sh"
  }
}