Unable to update to the latest version of Windows

Hello.
I am Japanese and this text is translated by DeepL. Sorry for any inadequacies. So I would appreciate it if you could reply in plain English if possible.
I cannot update from Windows ver 5.13.0 because I had turned off automatic updates.
I have four problems.
1. when I sign in, I get a message asking me to contact the IT team and I can't join a meeting and there is no update button.

2.When I try to uninstall 5.13 and install the latest version, the Windows installer says zoominstallerfull.msi(path) cannot be found and I cannot uninstall 5.13.0.

3. After gathering information, I found that the Microsoft Fixit utility was effective, so I downloaded and started it and uninstalled it, but the application icon is still in the Start menu and I can start it and it remains at 5.13.0. Also, I can no longer uninstall it from Windows Settings.

4. I cannot get technical support from the Japan office, and when I try to contact them by phone, they announce that they have no account information, but I can sign in from the web.

The only alternative would be to use the web version, but I would like to update the software if possible.

Translated with www.DeepL.com/Translator (free version)