Bank transfer is also supported via the online shop. Instead of a subscription, a non-reoccurring 5 year license is available for the SMA or Fronius connection.
SMA:
https://shop.solar-fox.com/products/sma-update-service?variant=39747058925656
Fronius:
https://shop.solar-fox.com/products/fronius-update-service?variant=39865106923608