I have Chrome extension and I'm injecting my app in to a web pages when the tab is loaded.

 chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
    if (changeInfo.status === 'complete') {
    // Inject app

And sometimes somepages load time is very slow, DOM can be already loaded but some stuff keeps loading and loading, so is there a BETTER time to inject my app? And how to detect it?