Actually I had a helpful suggestion for everyone to make on-screen keyboard enable in python for any operating system. Please review the code I used recently in a project:

Library:
pip install lib-platform

`def open_keyboard_dialog(self):
global onscreen
onscreen+=1
os_name = platform.system().lower()

    if os_name == 'darwin':
        cmd = [" /System/Library/Input Methods/KeyboardViewer.app/Contents/MacOS/KeyboardViewer" if onscreen%2!=0 else "killall KeyboardViewer"]
                    
        subprocess.Popen(
        cmd[0],
        stdout=subprocess.PIPE,
        stderr=None,
        shell=True,
            )

    elif os_name == 'windows':
        cmd = ["osk" if onscreen%2!=0 else " "]
                    
        subprocess.Popen(
        cmd[0],
        stdout=subprocess.PIPE,
        stderr=None,
        shell=True,
            )
                
    elif os_name == 'linux':
        cmd = ["onboard" if onscreen%2!=0 else "killall onboard"]
                    
        subprocess.Popen(
        cmd[0],
        stdout=subprocess.PIPE,
        stderr=None,
        shell=True,
            )`

I tried this & its helpful for almost any plateform.