After you've installed the onscreen keyboard, you'll see the following instruction window:

To display the Logitech Onscreen Keyboard, move your mouse cursor to the very left or right edge of the screen.

NOTE: To exit the instruction window, click the "X" in the upper right side of the screen, or move the cursor to the left or right edges of the screen.

When you move the mouse cursor to the left or right edge of the screen, the onscreen keyboard appears:

Additional information

For more information on Logitech Onscreen Keyboard features, see answer 360023189974.