Microsoft has reminded users that Windows 10, version 1909, will reach end of service next month, in May 2021. Customers advised to upgrade to latest on-premise or cloud versions as soon as possible to keep systems secure from attacks and bug-free. Windows 10 2004 is now in broad deployment and available to everyone via Windows Update. Microsoft is now also allowing a limited set of customers (with devices running Windows 10 1903 and later) to upgraded to Windows 10 20H2, the latest released version.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-windows-10-1909-reaches-end-of-service-next-month/