How to extract the email address from the body of the letter and send a standard response to it?

Question

gmail

Help with google script. It is necessary for incoming mail to stir up an auto-reply to the address taken from the text of the letter. The situation is as follows - mail (gmail) receives letters generated by a web form on the site. In these letters, the Name, Phone and Soap are indicated. It is necessary to take mail from the text and send a standard response to it ( something like - application accepted, thanks for contacting, we will contact you soon ). Tell me, if anyone can and knows how to implement this through Google Apps Script?
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The text of incoming emails is something like this:

*Request details:*
Name: Тест
Email: [email protected]
Phone: [phone]

Answer 1

In short, I solved the problem. I'll leave it here in case it's useful to someone.
In general, I made a plate with two identical sheets (New and Processed) of the form:

And I wrote the following code:

var name, email, phone;
name = email = phone = 'None';

function getEmails(){
  var threads = GmailApp.search('label:Заявка');

  if (threads.length) {
    for (var i=0; i < threads.length; i++) {
      var messages = threads[i].getMessages();
      for (var j=0; j < messages.length; j++) {
        var message = messages[j];
        message.markRead(); 
        extractDetails(message);
      }
      getSheetData();
      threads[i].removeLabel(GmailApp.getUserLabelByName("Заявка"));
      threads[i].addLabel(GmailApp.getUserLabelByName("Обработано"));
    }    
  } else {}
}

function extractDetails(message){
  var dateTime = message.getDate();
  searchInBody(message.getPlainBody());
  var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
  var activeSheet = SpreadsheetApp.setActiveSheet(spreadsheet.getSheetByName("Новые"));
  activeSheet.appendRow([dateTime, name, email, phone]);
}

function searchInBody(mes) {
  var lines, subline;
  lines = mes.split("\n");

  for (index = 0; index < lines.length; ++index) {
    if(lines[index].indexOf('Name:') + 1) {
      subline = lines[index].split(":");
      name = subline[1].toString().trim();
    }
    if(lines[index].indexOf('Email:') + 1) {
      subline = lines[index].split(":");
      email = subline[1].toString().trim();  
    }
    if(lines[index].indexOf('Phone:') + 1) {
      subline = lines[index].split(":");
      phone = subline[1].toString().trim().slice(1,);
    }
  }
}

function getSheetData() {
  var re = /\[email protected]\S+\.\S+/;
  var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = SpreadsheetApp.setActiveSheet(spreadsheet.getSheetByName("Новые"));
  var data = sheet.getRange('A2:F').getValues();
  sheet.getRange('A2:F').clearContent();
  
  data.forEach(row => {
    if (row[2] !== '' && re.test(row[2])) {
      sendMail();
    } else {}
  })

  var sheet1 = SpreadsheetApp.setActiveSheet(spreadsheet.getSheetByName("Обработанные"));
  var row = data.length;
  var column = data[0].length;
  sheet1.getRange(sheet1.getLastRow()+1, 1, row, column).setValues(data);
}

function sendMail() {
  var html = 'Здравствуйте '+name+'!<br><br>Ваша заявка принята, наш специалист скоро свяжется с вами.<br><br>Спасибо за обращение.';  
  var recipientsTO = email;
  var recipientsCC = email;
  var Subject = "Ваша заявка принята";
  
  MailApp.sendEmail({
    to: recipientsTO,
    cc: recipientsCC,
    subject: Subject,
    htmlBody: html
  });
}

Gave him the necessary permissions and set the schedule. The code is damp and far from optimal, but so far everything works.