Given a JSON string or a JSON file with Kindle highlights, this app allows the user to have offline access to his or her Kindle highlights directly on the Fitbit device.
A browser addon working on Chrome and Edge is available to generate the JSON file. See https://chrome.google.com/webstore/detail/my-kindle-highlights/codbcfademkhlblegiocccpaimimhkih
The hyperlink to be entered in the settings should be a direct download link. If you are using OneDrive to store the JSON file, you can follow the instructions at https://earns.io/tutorial-create-direct-download-link-onedrive/ in order to generate such a link.