why my webhook doesn't send files

[humber42]

I send with the webhook the image file encoded in Base64 but I never send it with the bot, how i can solve this?, I use Express Js
Response image

/*This is my webhook code//
const express = require('express');
const app = express();
const port = 3031;
const files = require("./images/files")

app.use(((req, res, next) => {
res.header("Access-Control-Allow-Origin", "*"); // update to match the domain you will make the request from
res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type,Accept");
next();
}))

app.post('/api/getting-files',((req, res) =>
res.send(
[{
"text": "Imagenes",
"type": "message",
"files": [
{
"name":"1.jpg",
"file":files.photo1
},
{
"name":"2.jpg",
"file":files.photo2
},
{
"name":"3.jpg",
"file":files.photo3
},
{
"name":"4.jpg",
"file":files.photo4
},
{
"name":"5.jpg",
"file":files.photo5
},
{
"name":"6.jpg",
"file":files.photo6
},
{
"name":"7.jpg",
"file":files.photo7
},
{
"name":"8.jpg",
"file":files.photo8
},
{
"name":"9.jpg",
"file":files.photo9
},
{
"name":"10.jpg",
"file": files.photo10
},
{
"name":"11.jpg",
"file":files.photo11
}
]
}
])
));

app.listen(port)