
Without your explicit permission, lembot cannot edit your Google Sheets and you will get a Google API error [403] The caller does not have permission.
Giving permission is super easy.
As easy as sharing the spreadsheet to your best friend, with editor rights.
Here your best friend is lembot which email is:
lembot@lembot.iam.gserviceaccount.com
Even easier but I do not recommend because it is less secured.
Click Get link, choose Anyone with the link and select Editor rights.
Cheers,
François