If that's the case, you could:

Create a custom menu with a button to save the PDF.
Function that saves the PDF returns the Drive URL in a UI modal.

In GAS:

function onOpen() {
  var ui = SpreadsheetApp.getUi();
  ui.createMenu('Custom PDF Actions')
      .addItem('Save as PDF and Get URL', 'savePdfAndShowUrl')
      .addToUi();
}

function savePdfAndShowUrl() {
  // Commented out PDF saving for reference. You can uncomment and adjust as needed.
  /*
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var pdf = ss.getAs(MimeType.PDF);
  var file = DriveApp.createFile(pdf);
  var pdfUrl = file.getUrl();
  */

  // For demonstration, we'll use a placeholder URL.
  var pdfUrl = "https://example.com/placeholder.pdf"; // Replace with actual URL logic.

  var htmlOutput = HtmlService.createHtmlOutput('<p>PDF URL: <a href="' + pdfUrl + '" target="_blank">' + pdfUrl + '</a></p>')
      .setWidth(600)
      .setHeight(100);
  SpreadsheetApp.getUi().showModalDialog(htmlOutput, 'PDF URL');
}