Converts CSV To JSON only. One way. For both ways go to https://apps.apple.com/us/app/csv-json-two-way-converter/id1608602049. Pick your file and pathway for both selection and download it to any directory/folder on your Mac. Pick any folder you want and use Mac's Automator to really make the JSON files productive. Avoid using unsafe web-based CSV to JSON converters. Running the conversion locally on your Mac also avoids web page crashes do to things like browsing caching.