Hello Vishnu Anand,
Welcome to microsoft Q&A, thankyou for posting your query here.
you can connect your USB device to your local machine and then use the plug-and-play option in RDP to connect the device to the Azure VM for code signing
It is important to make sure that the USB device is supported by the Azure VM and that the necessary drivers are installed on the VM.
To check if the USB device is supported by the Azure VM, you can connect the USB device to your local machine and then run the Remote Desktop client (mstsc.exe) to open the Remote Desktop client.
Select "Show Options" and then select the "Local Resources" tab. Under "Local devices and resources", select "More".
If your device is compatible, it should appear under "Other supported Remote FX USB devices". You can only use USB redirection on USB devices that appear in this list
To set the devicestoredirect RDP property, use these steps:
Open the Remote Desktop client (mstsc.exe) on your local machine.
Click on "Show Options" to expand the options.
Click on the "Local Resources" tab.
Click on the "More" button under "Local devices and resources".
In the "Local devices and resources" dialog box, select the "Drives" check box to enable drive redirection.
Click on the "OK" button to close the dialog box.
Click on the "Connect" button to connect to the Azure VM.
Yes, you can store your code signing certificates in Azure Key Vault.
You can use Azure Key Vault to store and manage your code signing certificates securely.
This will help you to protect your certificates from unauthorized access and ensure that they are available when you need them.
https://learn.microsoft.com/en-us/azure/key-vault/general/quick-create-portal
Once you have stored your code signing certificate in Azure Key Vault, you can grant access to the certificate to the users or applications that need to use it.
https://learn.microsoft.com/en-us/azure/key-vault/general/rbac-guide?tabs=azure-cli
Hope this helps you.