Hi Duy,
If you post details of your server and setup then it will be easier for people on here to help you.
- Shared or Dedicated Server?
- Did your setup the server or install Magento yourself?
- What are your server specifications?
- What version of Magento are you using?
- Were you following the tutorial How to setup Let’s Encrypt Free SSL Certificate with Magento 2 ?
- Have you flushed your browser’s cache?
- Was the website working before you installed SSL? (Looking at the website address right now, I can see http 599 error, ERR_CONNECTION_TIMED_OUT which is not specific to an SSL issue)
Looking forward to your reply so we can provide you some help on your issue.
Thanks