https://www.pbainbridge.co.uk/2023/03/read-write-multiple-user-properties.html

Read & write multiple User Properties.gs

function saveToProperties() {

  // save to User Properties in one go
  var userProperties = PropertiesService.getUserProperties();
  var newProperties = {
    sourceFolderId: '123',
    destinationFolderId: '456',
  };
  userProperties.setProperties(newProperties);

  Logger.log("Successfully stored User Properties");

}


function getFromProperties() {

  // run Function to get from User Properties
  var userProperties = PropertiesService.getUserProperties().getProperties();  // returns an Object
  Logger.log(userProperties);

  // log each item from User Properties
  Logger.log(userProperties.destinationFolderId);
  Logger.log(userProperties.sourceFolderId);

}