We use body-parser module to handle the request body in the Express framework. If you have not configured the BodyParser module properly you might end up getting error 

"Error: request entity too large"

To handle this error, you can specify the maximum size of entity in the body-parser module.

const express = require("express");
const bodyParser = require("body-parser");
const app = express();

// configure bodyparser

app.use(bodyParser.json({limit: '50mb'}));
app.use(bodyParser.urlencoded({ extended: false, limit: '50mb' }));

Configure the file size based on your project requirenment. This will fix the "request entity too large" error.