JavaScript Code

link - learn.microsoft.com/en-us/office/dev/add-ins/excel/excel-add-ins-workbooks 

Get Workbook Properties

Excel.run(function (context) { 
   const props = context.workbook.properties; 
   props.load([ 
      "title", "subject", "author", "comments" 
   ]); 
   await context.sync(); 
   console.log(props.author); 
} 

Close

Excel.run(function (context) { 
   context.workbook.close(Excel.CloseBehavior.save); 
}); 

Office.context.documents.getFilePropertiesAsync()