Hi, your best bet is to open up a Support Case with Microsoft directly.
The reason for this is there are some complexities with how Classic resources are managed.
If you wanted to try it yourself, this is what I would attempt:
- Try moving the resource into Bicep - https://video2.skills-academy.com/en-us/azure/templates/microsoft.compute/2020-10-01-preview/cloudservices?pivots=deployment-language-bicep
- Try editing the resource directly: https://resources.azure.com/
Attempt these in a test environment; obviously, moving to an ARM resource(from Classic) is preferred.