From the Glasp.co website:
YouTube Summary with ChatGPT is a free Chrome Extension that lets you quickly access the summary of the YouTube videos you are watching with OpenAI's ChatGPT AI technology. Use this extension to save time and learn quicker.
How it works: Install the Chrome or Safari extension and open any YouTube video. Click on the transcript & summary then on the ChatGPT icon to view the AI summary.
Pricing and terms: Free