In NextJS i have created an API that writes data to my local SQLite db. In dev it works perfectly but on prod i get a 504 Gateway Timeout. My app is self hosted in a VM on a centos with pm2 and nginx. I use cloudflare only as a reverse proxy for extra security. This is where i call the API

  useEffect(() => {
    const sendVisitorData = async () => {
      await fetch('/api', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json'
        }
      });
    };
    sendVisitorData();
  }, []);

This is my API:

export async function POST(request: Request) {
  try {
    await new Promise<void>((resolve, reject) => {
      db.serialize(() => {
        db.run(
          'INSERT INTO visitors (visittime, numOfClicks) VALUES (?, ?, ?, ?)',
          [visitTime, numOfClicks],
          (err: Error | null) => {
            if (err) {
              logError(err);
              reject(err);
            } else {
              resolve();
            }
          }
        );
      });
    });

    return NextResponse.json({ status: 'Visitor data stored' }, { status: 200 });
  } catch (error) {
    logError(error);

    return NextResponse.json({ error: JSON.stringify(error) }, { status: 500 });
  }
}

My nginx only listen for 443 ssl traffic and forwards that toward http://localhost:3000/ (pm2 runs on that port the page is loads correctly only the API not working)
I only allow traffic in from my router that is from Cloudflare’s IPs and only 443 port. In Cloudflare i have disabled cache for doamain.com/api