node https ssl your connection is not private error

Appearently it took some days to have the certification marked as safe here is the code at the end:

const express = require("express");
const https = require('https');
const helmet = require("helmet");
const cors = require("cors");
const fs = require("fs");
const path = require("path");
const app = express();
const config = require("./config");
const passport = require("passport");
const credentials = { key: fs.readFileSync('ssl/site.key', 'utf-8'), cert: fs.readFileSync('ssl/site.crt', 'utf-8'), ca: fs.readFileSync('ssl/site.ca-bundle', 'utf-8') };

app.use(helmet());
app.use(cors());
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(
  require("express-session")({
    secret: require("./config.json").app.secretKey,
    resave: false,
    saveUninitialized: true,
    cookie: {
      secure: false,
      maxAge: 60 * 60 * 1000 * 24 * 365,
    },
  })
);

app.use(passport.initialize());
app.use(passport.session());
passport.use(require("./service/passport"));

app.set("view engine", "ejs");
app.set("views", path.join(__dirname, "views"));
app.use(express.static(path.join(__dirname, "views")));

app.use('/', require('./api/home'));
app.use("/auth", require("./api/auth"));
app.use("/answer", require("./api/answer"));
app.use('/material', require('./api/material'));
app.use("/user", require("./api/user"));
app.use("/courses", require("./api/course"));
app.use('/feedback', require('./api/feedback'))
app.use("/question", require("./api/question"));
app.use("/answer", require("./api/answer"));

var httpsServer = https.createServer(credentials, app);

httpsServer.listen(config.app.port);

Also i used the certification that i generated via openssl and not the one i received from the website.

You need to collect the site certificate and the intermediate certificates into a single buffer and pass that combined buffer as the cert option to https.createServer(). So replace this:

const credentials = { key: fs.readFileSync('ssl/key.pem'), cert: fs.readFileSync('ssl/crt.pem'), ca: fs.readFileSync('ssl/ceraut.ca-bundle') };

with this:

const credentials = { key: fs.readFileSync('ssl/key.pem'), cert: fs.readFileSync('ssl/crt.pem') + fs.readFileSync('ssl/ceraut.ca-bundle') };

(This assumes that your ca-bundle file contains the intermediate certs in the correct order and in PEM format.) It's possible that you might also have to add a newline between the content of the two files if the closing newline from the site cert file has somehow been lost.

Don't pass a ca option to createServer() at all. That option specifies a non-default root cert collection that should be used to validate a received certificate. Your server doesn't need that option.

For details see https://nodejs.org/docs/latest-v10.x/api/tls.html#tls_tls_createsecurecontext_options or the equivalent for the appropriate Node version, although the precise version probably doesn't matter. The docs for these options have been stable for ages.