the notebook you linked needs to be updated. Since then we added many new tools to make batch processing easier, shown and explained in this sentinelhub-py batch notebook.
The results still need to be processed into eopatches, which is done in the notebook you linked. Another, more recent, example can be found here
DownloadFailedException: Failed to download from:
https://services.sentinel-hub.com/api/v1/batch/process
with HTTPError:
400 Client Error: Bad Request for url: https://services.sentinel-hub.com/api/v1/batch/process
Server response: "{"error":{"status":400,"reason":"Bad Request","message":"Request is estimated to create 7233.102112 output files. Requests over 5000 files must use 'overwrite = true' and 'skipExisting = false'","code":"COMMON_BAD_PAYLOAD"}}"
What is the meaning of overwriting existing outputs in this context?
These parameters are described in Batch API documentation. In the payload schema you can find them in output section. I recommend setting them according to instructions of the error message.
With SentinelHubBatch interface you can set them in the method: