There is no Windows 11. Microsoft has been releasing new feature builds while still maintaining the Windows 10 version. These builds come out typically in March/April and September/October
1803, 1809, 1903 and so forth. The current build available is 1909 which you can get in one of several ways.
- Wait until it is delivered via Windows Update
- Install it with the media creation tool Link Removed
- Use the update assistant (also at the link above)