https://www.pbainbridge.co.uk/2018/12/split-file-upload-url.html

Split Url File Upload.gs

function splitUrlFile(Url) {
  
  // remove this line when you incorporate into your script
  var Url = 'https://drive.google.com/open?id=1ZvhkehvoL99EmmzUsy481givp31odMaO';
  
  // split the Url via the equals sign to break into two
  var split = Url.split('=');
  
  // the file ID is the second part of the split (first part being zero)
  var uploadID = split[1];
  Logger.log('Upload file ID is: ' + uploadID); 
  
  // instruct DriveApp to open the file by its ID
  var file = DriveApp.getFileById(uploadID);
  Logger.log('File is: ' + file);
  
}