FROM ubuntu:20.04
...
CMD ["node", "main.js"]

FROM ubuntu:20.04
...
CMD ["node", "main.js"]

app.use(function (req, res, next) {
  res.setHeader(
    "Access-Control-Allow-Origin",
    process.env.FRONTEND_URL as string
  );
  res.setHeader("Access-Control-Allow-Credentials", "true");
  res.setHeader("Access-Control-Max-Age", "1800");
  res.setHeader("Access-Control-Allow-Headers", "content-type");
  res.setHeader(
    "Access-Control-Allow-Methods",
    "PUT, POST, GET, DELETE, PATCH, OPTIONS"
  );
  next();
});
app.use(
  cors({
    origin: process.env.FRONTEND_URL,
    credentials: true,
  })
);

app.use(function (req, res, next) {
  res.setHeader(
    "Access-Control-Allow-Origin",
    process.env.FRONTEND_URL as string
  );
  res.setHeader("Access-Control-Allow-Credentials", "true");
  res.setHeader("Access-Control-Max-Age", "1800");
  res.setHeader("Access-Control-Allow-Headers", "content-type");
  res.setHeader(
    "Access-Control-Allow-Methods",
    "PUT, POST, GET, DELETE, PATCH, OPTIONS"
  );
  next();
});
app.use(
  cors({
    origin: process.env.FRONTEND_URL,
    credentials: true,
  })
);

Access to XMLHttpRequest at 'https://<app_name>.up.railway.app/' from origin 'https://frontend.app' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The 'Access-Control-Allow-Origin' header has a value 'https://frontend.app/' that is not equal to the supplied origin.

Access to XMLHttpRequest at 'https://<app_name>.up.railway.app/' from origin 'https://frontend.app' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The 'Access-Control-Allow-Origin' header has a value 'https://frontend.app/' that is not equal to the supplied origin.