However the technology that powered the Internet Explorer (MSHTML and Trident Engine) will continue to remain in support till 2029. So yeah it's official that Internet Explorer is now out-of-support and is no longer usable.
What are the alternatives?
Well if you have been using internet explorer to this date then you might not be able to use any more as Microsoft completely ended the support for it. So if you have any saved passwords or any other information you might want to import in any other browser like Edge or Chrome, you can go for any other alternatives also. It's easy to export or import your data through any browser. For the steps you can find many articles on google to get help.