It’s been a while but for the records: Some SMA inverters neither have a web frontend to connect to, nor do they communicate modbus TCP or Speedwire (over Multicast). An example is the Sunny Boy 4000 (With green LC Display). These inverters cannot be integrated with the nice and stable SMA SOLAR integration provided by @emontnemery as those inverters are lacking a web server to poll. If your inverter is configured with the SUNNY EXPLORER application (as an idicator of legacy) you may need to use a physical RTU connection to ingest the legacy YASDI formatted data. See instructions here:
https://community.home-assistant.io/t/best-way-to-connect-sma-sb-4000tl-20-to-ha/390754