Hi, I'm Bernard, a fellow Windows user. I'm happy to help!
Unfortunately, the functionality to move the taskbar vertically has been removed in Windows 11. And there is no news if that will get back. Moreover, since this is a limitation of Windows 11, I recommend submitting your ideas or suggestions about the taskbar to the feedback hub.
To send Feedback: https://support.microsoft.com/en-us/windows/send-feedback-to-microsoft-with-the-feedback-hub-app-f59187f8-8739-22d6-ba93-f66612949332
Let me know how it goes, and I hope that helps.