So. I am trying to write a simple extension to better understand JS(and extensions in general). I took info from google's FAQ but I get an error in line 4 (tabID?). Any tips?

var timetoupdate = 500 * 60;

chrome.tabs.reload(
  tabId?: number,
  reloadProperties?: object,
  callback?: function,
);

setTimeout(chrome.tabs.reload, timetoupdate);

This is from init.js that is loaded by manifest.json