The Tilt URL in the Grainfather instructions is used as an example.
To get your personal logging Tilt URLs, you need to add your Tilt devices to your account in the equipment page under 'Fermentation Tracking Equipment'.
When adding them, you will need to select the same colours as the Tilts that you own. Once you have added a new Tilt to your Grainfather account, tap on it to open it up and then tap the options button in the top right corner and select 'View Setup Instructions' - this instructions page will display the unique logging URL for that Tilt.