Adding a drive doc to an existing AppScript email as an attachment

The documentation for Advanced parameters explains that attachments are an array of files to send with the email. To add another attachment from the drive with a docID,

Change:

    var attachments = []
    var file = DriveApp.getFileById("1vGvLVP2RV1krxnj8Mt6hMiFHVBoIdbFG");
    attachments.push(file.getAs(MimeType.PDF));


    MailApp.sendEmail({
      to: email,
      subject: subject,
      body: messageBody,
      attachments: [blob.getAs(MimeType.PDF)]
    });

    Logger.log(row);
    file.setTrashed(true);
  })

To:

    var docFile = DriveApp.getFileById("1vGvLVP2RV1krxnj8Mt6hMiFHVBoIdbFG").getAs(MimeType.PDF);

    MailApp.sendEmail({
      to: email,
      subject: subject,
      body: messageBody,
      attachments: [blob.getAs(MimeType.PDF), docFile]
    });

    Logger.log(row);
    file.setTrashed(true);
  })

Here's a modified version of your script that should achieve what you'd like:

const SHEETID = '1rx1lCYKdhi8dhivoYpUO6EIHb2TWTpiMVduK7M-L2A4';
const DOCID = '1sRZqPCkuATT9tQDZlJDp-DicP6saBpZoAXVvKWXT_XM';
const FOLDERID = '1wsyrUM29A1LIiKCjsJE7olKb0ycG2_M5';

// Renamed to "pitchFees2026"
function pitchFees2026() {
  const sheet = SpreadsheetApp.openById(SHEETID).getSheetByName('2026 Fees');
  const temp = DriveApp.getFileById(DOCID);
  const folder = DriveApp.getFolderById(FOLDERID);

  // Declared the second attachment outside of the loop
  const docFile = DriveApp.getFileById("1vGvLVP2RV1krxnj8Mt6hMiFHVBoIdbFG").getAs(MimeType.PDF);
  const data = sheet.getDataRange().getValues();
  const rows = data.slice(1);
  rows.forEach((row) => {
    const file = temp.makeCopy(folder);
    const doc = DocumentApp.openById(file.getId());
    const body = doc.getBody();
    // Key-value pair of the data to be replaced
    const r = {
      "{NAME}": row[1],
      "{PITCH}": row[0],
      "{AMOUNT}": row[3],
      "{FIRST}": row[4],
      "{SECOND}": row[5],
      "{REF}": row[10],
      "{BNAME}": row[7],
      "{CODE}": row[8],
      "{NUMBER}": row[9],
      "{TERMS}": row[6]
    }
    // Handles all text replacements in a single loop
    Object.entries(r).forEach(([s, r]) => {
      body.replaceText(s, r);
    });
    doc.setName(row[10]);
    doc.saveAndClose();
    const blob = doc.getAs(MimeType.PDF);

    folder.createFile(blob).setName(row[10] + '.pdf');

    const email = row[2];
    const subject = row[10];
    const messageBody = "This message (including any attachments) is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination, or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. \n \nIf you received this in error, please delete the material from your computer and contact the sender. \n\nPlease consider the environment before printing this e-mail.";

    MailApp.sendEmail({
      to: email,
      subject: subject,
      body: messageBody,
      // Removed ".getAs(MimeType.PDF)" and added "docFile"
      attachments: [blob, docFile]
    });

    Logger.log(row);
    file.setTrashed(true);
  })
}

REFERENCES

• sendEmail(recipient, subject, body, options)
• Camel case
• Object.entries()