Change Script in Published app

changescriptinpublishedapp.js

const qsocks = require('qsocks');
const fs = require('fs');

// Our Qlik Sense Certificates
const client = fs.readFileSync('C:\\ProgramData\\Qlik\\Sense\\Repository\\Exported Certificates\\.Local Certificates\\client.pem');
const client_key = fs.readFileSync('C:\\ProgramData\\Qlik\\Sense\\Repository\\Exported Certificates\\.Local Certificates\\client_key.pem');

const config = {
    host: 'localhost',
    port: 4747, // Standard Engine port
    isSecure: true,
    headers: {
        'X-Qlik-User': 'UserDirectory=Internal;UserId=sa_repository' // Passing a user to QIX to authenticate as
    },
    key: client_key,
    cert: client,
    rejectUnauthorized: false, // Don't reject self-signed certs
    appname: '0caa24a6-4c7c-4915-8dc8-e42f3e10dfe6' // The app GUID we are going to be conneting to
};

qsocks.Connect(config).then(function(global) {
    // Access to the global class
    // Open document - Here we open the doc without data to not overload the server.
    // http://help.qlik.com/en-US/sense-developer/2.2/Subsystems/EngineAPI/Content/Classes/GlobalClass/Global-class-OpenDoc-method.htm
    return global.openDoc(config.appname, '', '', '', true);
    
})
.then(function(app) {
    // Access to the app class.
    // http://help.qlik.com/en-US/sense-developer/2.2/Subsystems/EngineAPI/Content/Classes/AppClass/App-class.htm
    
    // Our new load script
    var newScript = "Characters:\r\nLoad Chr(RecNo()+Ord('A')-1) as Alpha, RecNo() as Num autogenerate 26;";
    
    // Return a empty localized script
    return app.getEmptyScript('Main').then(function(result) {
        // Set the new loadscript, reload and save.
        return app.setScript(result + newScript)
            .then(function() {
              return app.doReload();
            })
            .then(function() {
              return app.doSave();
            })
    })
})
.catch(function(err) {
    console.log(err) // Handle error
})