To activate the Windows 10 touch keyboard through a shortcut or command line, you can follow these steps:
1. Right-click on an empty space on your desktop and select "New" > "Shortcut".
2. In the "Create Shortcut" window, type the following command: `explorer.exe ms-screenclip:?Microsoft.ScreenClip.TouchKeyboard`
3. Click "Next" and give the shortcut a name, such as "Touch Keyboard".
4. Click "Finish" to create the shortcut on your desktop.
Now, whenever you want to activate the touch keyboard on your second monitor, simply double-click on the shortcut you just created. This will launch the touch keyboard on your primary monitor, and you can easily drag it to your second monitor.
Alternatively, you can use the keyboard shortcut "Win + R" to open the "Run" dialog box, and then enter the command `explorer.exe ms-screenclip:?Microsoft.ScreenClip.TouchKeyboard` to activate the touch keyboard.
I hope this information helps! Let me know if you have any further questions.