Access to fetch at [URL] from origin [URL] has been blocked by CORS Policy.
No 'Access-Control-Allow-Origin' header is present on the requested resource.

const cors = require('cors')({ origin: true });

app.get('/my-route', (req, res) => {
    return cors(req, res, () => {
        res.render('view-report-template', context, (err, html) => {
        res.status(200).send(html);
    });
});

const cors = require('cors')({ origin: true });

app.get('/my-route', (req, res) => {
    res.render('view-report-template', context, (err, html) => {
        res.status(200).send(html);
    });
});

app.use(cors);

app.use((req, res, next) => {
    res.header("Access-Control-Allow-Origin", "*");
    res.header('Access-Control-Allow-Methods', 'DELETE, PUT, GET, POST');
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With,
Content-Type, Accept");
    next();
});

app.get('/my-route', (req, res) => {
    res.render('view-report-template', context, (err, html) => {
        res.status(200).send(html);
    });
});

app.use((req, res, next) => {
    res.header("Access-Control-Allow-Origin", "*")
    res.header(
        "Access-Control-Allow-Headers",
        "Origin, X-Requested-With, Content-Type, Accept, Authorization"
    );
    if(req.method === 'OPTIONS'){
        res.header('Access-Control-Allow-Methods', 'PUT, POST, PATCH,
DELETE, GET');
        return res.status(200).json({});
    }
    next();
});

app.get('/my-route', (req, res) => {
    res.render('view-report-template', context, (err, html) => {
        res.status(200).send(html);
    });
});

app.get('/my-route', (req, res) => {
    res.set('Access-Control-Allow-Origin', '*');
    res.status(200).send(html);
});

fetch('https://us-central1-[project-id].cloudfunctions.net/my-route', {
     method: "GET",
     mode: "cors"
 })
  .then(res => res.text())
  .then(data => console.log(data));