Extended Support ended January 14, 2020, however Microsoft is offering Extended Security Updates (ESU) until January, 2023. It's a paid program to extend security patches, having to be paid once a year for each of the 3 years; so only truly desperate companies are paying for this privilege.
[1] https://docs.microsoft.com/en-us/lifecycle/faq/extended-secu...
[2] https://techcommunity.microsoft.com/t5/windows-it-pro-blog/y...