Go into the settings page in Brewfather APP, enable Brewpiless. You will then get a URL, Data Type and Format that you need to copy into the Brewpiless remote logging configuration page.
Set log time period to 900 seconds. Your Brewpiless should then log every 15 minutes.
After the Brewpiless has done its first logging to Brewfather, it will appear in the device list located in your Batch > Fermentation > Readings > Devices. Click on the Devices button and attatch your Brewpiless to the batch. The next time your Brewpiless logs, it will show up in your batch!
Never log more than once every 15 minutes, request logged more often than that will be ignored.