Using script to send one sheet in Google sheets not working - google-apps-script

Question

I am using this code: https://stackoverflow.com/a/45781391/13875010
I only want to send sheet #3 to the email address located in cell A1 on sheet three.
I run the script and nothing happens.
What am I doing wrong?
function sendSheetToPdfwithA1MailAdress(){ // this is the function to call
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sh = ss.getSheets()[3]; // it will send sheet 0 which is the first sheet in the spreadsheet.
// if you change the number, change it also in the parameters below
var shName = sh.getName()
sendSpreadsheetToPdf(3, shName, sh.getRange('A1').getValue(),"test email with the address in cell A1 ", "This is it !");
}
function sendSpreadsheetToPdf(sheetNumber, pdfName, email,subject, htmlbody) {
var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
var spreadsheetId = spreadsheet.getId()
var sheetId = sheetNumber ? spreadsheet.getSheets()[3].getSheetId() : null;
var url_base = spreadsheet.getUrl().replace(/edit$/,'');
var url_ext = 'export?exportFormat=pdf&format=pdf' //export as pdf
+ (sheetId ? ('&gid=' + sheetId) : ('&id=' + spreadsheetId))
// following parameters are optional...
+ '&size=A4' // paper size
+ '&portrait=true' // orientation, false for landscape
+ '&fitw=true' // fit to width, false for actual size
+ '&sheetnames=true&printtitle=false&pagenumbers=true' //hide optional headers and footers
+ '&gridlines=false' // hide gridlines
+ '&fzr=false'; // do not repeat row headers (frozen rows) on each page
var options = {
headers: {
'Authorization': 'Bearer ' + ScriptApp.getOAuthToken(),
}
}
var response = UrlFetchApp.fetch(url_base + url_ext, options);
var blob = response.getBlob().setName(pdfName + '.pdf');
if (email) {
var mailOptions = {
attachments:blob, htmlBody:htmlbody
}
MailApp.sendEmail(
email,
subject+" (" + pdfName +")",
"html content only",
mailOptions);
MailApp.sendEmail(
Session.getActiveUser().getEmail(),
"FRWD "+subject+" (" + pdfName +")",
"html content only",
mailOptions);
}
}

Answer 1

I was using the wrong number...Sheet 3 is number 2.