@J P Apologies for the delayed response. Based on the information you provided, it seems that you have followed the necessary steps to use the Trusted Signing service on Windows 10 (22H2). However, the error message you received when running signtool.exe indicates that there may be an issue with the parameters you are using.
Regarding the comment you mentioned from https://melatonin.dev/blog/code-signing-on-windows-with-azure-trusted-signing/, it is possible that the new signtool.exe may not work on older versions of Windows. However, Windows 10 (22H2) is a relatively recent version, so it should be compatible with the latest signtool.exe.
To troubleshoot the issue further, I would recommend checking the parameters you are using with signtool.exe to ensure they are correct. You may also want to try running signtool.exe with different parameters or on a different file to see if the issue persists.
If the issue still persists, you can try reaching out to our support team, if in case you don't have support contract, feel free to share the Azure Subscription id over the private message so that we can help in creating a one-time support option for this issue.