The sheet, key and JSON are all correct- they have been the same for the two years. The issue at the moment is just creating/editing data rather than getting/requesting it (unless I’ve misunderstood how requestasync is used).
I have searched for any update log for the Google Sheets API and I haven’t found anything relevant to this issue. The code for adding data is in the screenshot above, if I were to overwrite/edit data I would use the same function. Data is only ever removed manually for security sake.
The macro script is found in the tutorial. Which I barely understand aha.