Omada Controller v5+ and the ER gateways support a Custom DDNS entry that works with any DynDNS2 provider. With DNS Beacon your site stays reachable under a permanent hostname even when your WAN IP changes. Here's how to configure it.
Settings → Services → Dynamic DNS (or Device Config → DNS → Dynamic DNS)
Works with Omada Controller v5+ and gateway firmware that exposes a Custom DDNS entry (ER605, ER7206 and similar). Pick "Custom" as the Service Provider and create a new Dynamic DNS entry — Omada substitutes [DOMAIN], [IP], [USERNAME] and [PASSWORD] in the URL automatically.
Create a free DNS Beacon account, add a hostname and generate an API key — then come back and finish the setup above.
Create free account