The Properties Service of Google Apps Script is used by developers to store app configuration and user specific settings. The properties data is scoped to a specific user, or a specific project, and cannot be shared between different projects. … In some specific cases, we may want to give access to our store data to another user so they may build upon the existing configuration rather than having to build everything from scratch.
Amit Agarwal shares a useful snippet for letting users export and import data from
Source: How to Share User Properties between Google Apps Script Projects – Digital Inspiration
Member of Google Developers Experts Program for Google Workspace (Google Apps Script) and interested in supporting Google Workspace Devs.