To add a new keyboard layout on Windows 10, use these steps:
Open Settings.
Click on Time & Language.
Click on Language.
Under the "Preferred languages" section, select the default language.
Click the Options button.
Under the "Keyboards" section, click the Add a keyboard button.
Select the new keyboard layout you want to use. Repeat steps No. 6 and 7 to add more layouts.
Once you complete the steps, the new keyboard layout will be added to the device.