Problem with SSL in Chrome (hostinger, letsencrypt)

Question

I have this problem:

Failed to load resource: net::ERR_SSL_PROTOCOL_ERROR
There was an error! TypeError: Failed to fetch

I'm trying to make https POST or GET request to the server

This problems happens only in Chrome browser (Firefox, postman works ok)

I made a simple server:

const express = require('express');
const cors = require('cors');
const fs = require('fs');
const https = require('https');
const bodyParser = require('body-parser');

const app = express();

// CORS middleware to allow cross-origin requests
app.use(cors());

// Parse JSON request body
app.use(bodyParser.json());

app.post('/hello_world', (req, res) => {
    const { data } = req.body;
    // Your logic...
    res.status(200).send("Your response");
});

// SSL certificate
const options = {
    key: fs.readFileSync('/etc/letsencrypt/live/myhostname.com/privkey.pem', 'utf8'),
    cert: fs.readFileSync('/etc/letsencrypt/live/myhostname.com/cert.pem', 'utf8'),
    ca: fs.readFileSync('/etc/letsencrypt/live/myhostname.com/chain.pem', 'utf8')
};

const httpsServer = https.createServer(options, app);

// Listen on either port 443 for https production server
httpsServer.listen(443, () => {
    console.log('HTTPS Server running on port 443');
});

Request (frontend):

        const response = await fetch("https://myhostname.com/hello_world", {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({data: "123"}),
        });
        const rebus = await response.json();

Certificates created with:

certbot certonly -d myhostname.com

What could be the problem and how to understand the reason?

I tried other browsers (Firefox works well and postman also)