rheajt

function openTab() {
  var selection = SpreadsheetApp.getActiveSheet().getActiveCell().getValue();
  
  var html = "<script>window.open('" + selection + "');google.script.host.close();</script>";
  
  var userInterface = HtmlService.createHtmlOutput(html);
  
  SpreadsheetApp.getUi().showModalDialog(userInterface, 'Open Tab');
}