What’s kiosk mode?
If you go to fast food market, you may use vendor machine/self-assist machine to complete your shopping tasks. The applications in the modern operating systems we called kiosk. 
Kiosk mode in MS edge
The tutorials posted by Microsoft were for in private mode, which cannot retain users’ session data (e.g. IndexDB, Local Storage).
There is a convenient command you can use for keeping user session data. 
start msedge --kiosk --app=<your_website>
If you want to keep the session data in a specific folder, you can add
--user-data-dir parameter. But, it will automatically open the browser in full screen mode. .
start msedge --kiosk --app=<your_website> --user-data-dir=<your_session_folder_path>
- “Chrome Kiosk Mode”, URL: https://dandelion-burdock.com/articles/chrome-kiosk-mode
- Microsoft, “Configure Microsoft Kiosk Mode”, URL: https://learn.microsoft.com/en-us/deployedge/microsoft-edge-configure-kiosk-mode
- “認識 Google Chrome 與 Microsoft Edge 的 Kiosk 模式”, URL: https://blog.miniasp.com/post/2022/08/25/Enable-Kiosk-Mode-in-MS-Edge-and-Google-Chrome
- Microsoft, “Create Microsoft Edge user data directory variables”. URL:https://learn.microsoft.com/en-us/deployedge/edge-learnmore-create-user-directory-vars