1688-chrome-extension/background.js

chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
  if (changeInfo.status === 'complete' && tab.url == "https://shopkager.com/cart/detail") {
    chrome.scripting
      .executeScript({
        target: { tabId },
        files: ["inject.js"],
      })
      .then(() => console.log("script injected"));
  }
});