Fatal error: Unable to load file

packaging elctron with electron-packager will successfully generate a complete folder.
1: 'npm install --save-dev electron-winstaller'
2: then create a new build.js in the root directory . the code is as follows
`var electronInstaller = require('electron-winstaller');
console.log(1)
var path = require("path");
console.log(2)
resultPromise = electronInstaller.createWindowsInstaller({
appDirectory: path.join('./appssss-win32-x64'),
outputDirectory: path.join('./installer64'),
authors: '_w',
exe: "appssss.exe",
setupIcon: "./20.ico",
// iconUrl: '',
noMsi: true,
setupExe:'appssss.exe',
title:'appssss',
description: "version1.0.0"
});
resultPromise.then(() => console.log("It worked!"), (e) => console.log(`No dice: ${e.message}`));`
3: an error occurs when build.js is executed (node build.js) **Output Fatal error: Unable to load file**
console.log(1)and (2) have an output