MEVN stack unable to deploy - node.js

Question

I have a project where I try to locally and on Heroku run a MEVN application. Both are not working at the moment.
I have my server.js file in the main folder. Then inside the 'client' folder is the Vue 3 project. Inside there I have run npm run build which created a dist folder containing the index.html file.
When I run both locally and on Heroku I can go to '/api/users' and the JSON is shown in the browser. But when I navigate to '/'
I have tried changing the public in the server.js to dist but this did not fix the problem.
I get the following error: Error: ENOENT: no such file or directory, stat /Users/stephen/Documents/stephen/project/client/build/index.html
My server.js file looks like this:
const express = require("express");
const mongoose = require("mongoose");
const bodyParser = require("body-parser");
const path = require("path");
const cors = require("cors");
const app = express();
//Bodyparser Middleware
app.use(bodyParser.json());
app.enable("trust proxy");
app.use(cors());
app.use(function (req, res, next) {
res.header("Access-Control-Allow-Origin", '*');
res.header("Access-Control-Allow-Credentials", true);
res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS');
res.header("Access-Control-Allow-Headers", 'Origin,X-Requested-With,Content-Type,Accept,content-type,application/json');
next();
});
//DB Config
const db = require("./config/keys").mongoURI;
//Connect to Mongo
mongoose
.connect(db, {
useNewUrlParser: true,
useUnifiedTopology: true,
})
.then(() => console.log("MongoDB Connected"))
.catch((error) => console.log(error));
app.get('/api/users', (req, res) => {
res.json({ user: 'test' })
})
app.get('/', (req, res) => {
res.sendFile(path.join(__dirname, '/client/build/index.html'));
});
const port = process.env.PORT || 3000;
if (process.env.NODE_ENV === "production") {
app.use(express.static("client/build"));
app.get("*", (req, res) => {
res.sendFile(path.resolve(__dirname, "client", "build", "index.html"));
});
}
app.listen(port, () => console.log("Server starter on port " + port));