gsheets-append-action

Inputs

Input	Required	Default	Description
GOOGLE_USER_MAIL	true		The user ID to authenticate the service account user.
GOOGLE_USER_KEY	true		The users private key to authenticate the service account user.
SPREADSHEET	true		The spreadsheet ID to append the data to.
DATA_FILE_PATH	false		The csv file containing the data to upload. Use either this or DATA_ENV_NAME. NOTE: If DATA_FILE_PATH is configured, DATA_ENV_NAME will be ignored.
DATA_ENV_NAME	false		The environment variable containing the data to upload in CSV format. Use either this or DATA_FILE_PATH. NOTE: If DATA_FILE_PATH is configured, DATA_ENV_NAME will be ignored.
TABLE_START_CELL	false	A1	The cell that defines the "table anchor" in the format sheetName!A1.
UPDATE	false	false	Update or append data.

About private key

If you use GitHub Secrets to store a JSON private key, be mindful that you need to change all embedded \n linebreaks with real ones.

Given your JSON's private_key content is along the lines of:

-----BEGIN PRIVATE KEY-----\nBLABLABLABLABLA\nBLABLABLABLABLA\n-----END PRIVATE KEY-----\n

Change it to:

-----BEGIN PRIVATE KEY-----
BLABLABLABLABLA
BLABLABLABLABLA
-----END PRIVATE KEY-----

And use that as your GOOGLE_USER_KEY input.

Credit: https://github.com/dibenlloch/google-sheets-secrets-action

For action authors

After editing the action, run npm ci to regenerate dist/ and put edits into effect.