How to fix the issue mail merge issue - google-apps-script

Question

I am trying to create an approval flow using sheet mail merge with approval buttons in the mail . Mail could generate when the user submits the HTML form.
Below script is not working I have attached the script with sample sheet.
I am not able to identify the exact issue, please help me to fix or identify
Sample Sheet
var REQUESTS_STATE_COLUMN = 32;
var STATE_APPROVERS_EMAILED = "EMAILED_Response Pending";
var STATE_APPROVED = "Approved";
var STATE_DENIED = "Rejected";
function sendEmail(e) {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = SpreadsheetApp.getActiveSheet();
var dataRange = sheet.getRange("A2:AH2");
var data = dataRange.getValues();
for (i in data) {
var rowData = data[i];
var email = e.namedValues["Email Address"];
var emailAddress = rowData[30];
var submiterEmail = rowData[1];
var ProjectName = rowData[2];
var SrDesign = "Sr. Design Architect Services";
var PerHourRate = rowData[6];
var NumberOfHours = rowData[7];
var TotalRate = rowData[8];
var Contact = "Contact Centre Expert";
var PerHourRate2 = rowData[10];
var NumberOfHours2 = rowData[11];
var NTotalRate2 = rowData[12];
var NJrDesign = "Jr. Design Architect";
var PerHourRate3 = rowData[14];
var NumberOfHours3 = rowData[15];
var TotalRate3 = rowData[16];
var Outsourced = "Outsourced Technical Support Resource";
var PerHourRate4 = rowData[18];
var NumberOfHours4 = rowData[19];
var TotalRate4 = rowData[20];
var Supplier = "Supplier Management";
var PerHourRate5 = rowData[22];
var NumberOfHours5 = rowData[23];
var TotalRate5 = rowData[24];
var Project = "Project Management & Execution";
var PerHourRate6 = rowData[26];
var NumberOfHours6 = rowData[27];
var TotalRate6 = rowData[28];
var UserAccount = rowData[28];
var GrandTotalRate = rowData[29];
var seq = e.values[1];
var url = ScriptApp.getService().getUrl();
var sheet = SpreadsheetApp.openById('1i5x0oqpCDgOZO2Nbly4SpNkWpLbTXJhT6pPOfQ7NuEc').getSheetByName("Sheet1");
var cellval = range.getCell(row,1).getValue();
var options = '?approval=%APPROVE%&reply=%EMAIL%'
.replace("%EMAIL%",e.namedValues["User Email Address"])
var approve = url+options.replace("%APPROVE%","Approved")+'&row='+data+'&cellval='+cellval;
var reject = url+options.replace("%APPROVE%","Rejected")+'&row='+data+'&cellval='+cellval;
var subject = 'Technology Charges for '+ProjectName+'';
var html = '<p style="font-family:Verdana; fontsize=9px">Hello Recipient,<br/><br/><br/><br/>Referance No: '+cellval+'<br/><a href='+ approve +'> <b>approve </b></a><a href='+ reject +'> <b>Reject</b></a><br/>'
MailApp.sendEmail({
to: emailAddress,
subject: subject,
htmlBody: html,
});
//Add a state in the form spreadsheet with APPROVERS_EMAILED state
var sheet = SpreadsheetApp.getActiveSheet();
var lastRow = sheet.getLastRow();
sheet.getRange(lastRow, REQUESTS_STATE_COLUMN+1).setValue(STATE_APPROVERS_EMAILED);
}
}
function doGet(e){
var answer = (e.parameter.approval === 'Approved') ? 'Yes -Approved!' : 'No-Rejected ';
var cellval = e.parameter.cellval;
var email = e.parameter.reply;
var sheet = SpreadsheetApp.openById("1i5x0oqpCDgOZO2Nbly4SpNkWpLbTXJhT6pPOfQ7NuEc").getSheetByName("Sheet1");
var data = sheet.getDataRange().getValues();
var headers = data[0];
var approvalCol = headers.indexOf("Approval") + 1;
if (0 === approvalCol) throw new Error ("Must add Approval column.");
// Record approval or rejection in spreadsheet
var row = ArrayLib.indexOf(data, 0, cellval);
if (row < 0) throw new Error ("Request not available."); // Throw error if request was not found
sheet.getRange(row+1, approvalCol).setValue(e.parameter.approval);
// Display response to approver
var app = UiApp.createApplication();
app.add(app.createHTML('<h2>Thank you..! Your response has been recorded'+' saying: '+ answer + '</h2>'))
return app
}

Answer 1

The getCell requires integer value for row and column but instead you are passing the entire row (rowData). You need to replace the line 45 to the below line.
var cellval = dataRange.getCell(i+1, 1).getValue()