How to make Invoice line level DFF context value mandatory based on Supplier Type

Summary:

Making Invoice line level DFF context value mandatory (conditionally) if the supplier is Electricity provider

Content (required):

AP team wants to ensure that invoice processor doesn't miss to enter value on invoice line level DFF if the supplier is Electricity provider.

AP team fetches data of power consumption (units consumed) to be published in a business report.

Making context value mandatory would affect all the invoices. Would like to know if there is another workaround.

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):