Get Google Spreadsheet as PDF with customizations

Code.gs

function spreadsheetToPDF(key) {

  var spreadsheet = SpreadsheetApp.openById(key);
  var response = UrlFetchApp.fetch(spreadsheet.getUrl() + '/export?exportFormat=pdf&gid=1&gridlines=0&printtitle=0&size=7&fzr=true&portrait=1&fitw=1', {
    muteHttpExceptions: true,
      headers: { 
        Authorization: 'Bearer ' +  ScriptApp.getOAuthToken(),
      }
  });

  return response.getBlob();
}