is there a way to create automatic mails for Birthdays per Sheets and Scripts? So far, i got it to trigger with a button but now i would love to automate it. birthdate, mail and name are always listed on sheets and should trigger when the date is today, no matter the year (dd.mm). I will post my code below:

function GeburtstagsMail(e) {
  // Add a custom menu to the spreadsheet.

  SpreadsheetApp.getUi() // Or DocumentApp, SlidesApp, or FormApp.
      .createMenu('Geburtstag')
      .addItem('Senden', 'sendEmail')
      .addToUi();
  
  sendEmail();
  
  SpreadsheetApp.getUi() // Or DocumentApp, SlidesApp, or FormApp.
      .createMenu('Benachrichtigung')
      .addItem('Senden', 'Bmail')
      .addToUi();
  
 Bmail();
}

function sendEmail(){
  const sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
  const ui = SpreadsheetApp.getUi();
    
  var startRow = 2; // First row of data to process
  //(starting row index, starting column index, # or rows, # of columns)
  var dataRange = sheet.getRange(startRow, 1, sheet.getLastRow()-1,200);

  
  // Fetch values for each row in the Range.
  var data = dataRange.getValues();
  
  //Logger.log(data);

  var name;
  var birthdate;
  var emailAddress;

  var today = new Date();

  var rowNum=2;
  for (var i in data) {
    var row = data[i];
     
    name = row[0];
    birthdate = row[2];
    emailAddress = row[3];
    Logger.log(" i = "+i);
    /*
    Logger.log("today.getDay() "+today.getDate()+" today.getMonth() "+today.getMonth()+"n");
    Logger.log("birthdate.getDay() "+birthdate.getDate()+" birthdate.getMonth() "+birthdate.getMonth()+"n");
    */
    Logger.log("name "+name+" email "+emailAddress+" birthdate "+birthdate);
    if((today.getDate()==birthdate.getDate()) && (today.getMonth()==birthdate.getMonth())){
        
        Logger.log("name "+name+" email "+emailAddress+" birthdate "+birthdate);
        var body = "Hallo "+name+",nn"+
                "wir wünschen Dir alles Gute zum Geburtstag <3 <3 <3 <3nn"+
                "Feier schön mit Deinen Liebsten und lasse es Dir mal gut gehen. ;-)nn"+ 
                "<3 <3 <3nn"+                 
                "Viele Grüße senden Dirn"+
        var subject = 'Geburtstagsgruß';
        
        if(emailAddress!=null){
            MailApp.sendEmail(emailAddress, subject, body);
            sheet.getRange(rowNum, 6,1,1).setValue("Gesendet am "+new Date());            
        }
    } 
    rowNum++;   
  }  
}
 

As mentioned on top, i tried it so far with buttons which worked fine. After trying to set triggers it always ends up “failing”