Unfortunately, Railway doesn't provide A records—we only support CNAME-based DNS configuration since our infrastructure uses dynamic IPs. So there's no direct way to point your apex domain to Railway when your DNS provider doesn't support CNAME flattening or ALIAS records at the root level.

Your current redirect approach (IONOS redirecting example.com → https://www.example.com) is a perfectly valid workaround. In this case, you should NOT add example.com as a custom domain in Railway since you can't create the required DNS record—Railway wouldn't be able to verify or serve traffic for it anyway.

The better long-term solution is to switch your DNS management to Cloudflare while keeping your domain registered at IONOS. Cloudflare's free tier automatically handles CNAME flattening at the apex, so you'd just create a CNAME record for @ pointing to your Railway target and it works.

We suggest that you'd change your nameservers at IONOS to point to Cloudflare, then manage all your DNS records there. Here's their setup guide: Full DNS Setup

If you'd rather not switch DNS providers, your redirect setup is totally fine—users hitting example.com will seamlessly end up at www.example.com which Railway serves correctly.