Take a template Google Sheet (containing fields for 3 signatures) and copy it into other Google Sheet files within a given Google Drive folder and then reorder those sheets so that it was the first one.
The idea was based around needing users to authorise student marks with their signature from multiple Google Sheet reports produced from a third party system.
Source: The Gift of Script: Copy template sheet to Google Sheets and reorder
I use Google Apps Script to support staff and students in my job. I enjoy dabbling with creating tools to help with automation and I freely share my learning experiences on my blog: www.pbainbridge.co.uk