JAVASCRIPT

next js build command

...
"scripts": {
    "build": "next build",
    "start": "next start",
    "export": "next export"
}
...


// build command

$ npm run build 
$ npm run start

nextjs run command before build

For any prebuild steps, just add the "prebuild" property to your package.json's "scripts" property:

{
  ...
  "scripts": {
    "build": "next build",
    "postbuild": "node ./path-to/my-prebuild-script.mjs",
    "dev": "next dev",
    "start": "next start",
    "lint": "next lint"
  }
  ...
}