How to make the Legal Entity field required when creating a contract?

Summary:

Our business users would like to make the Legal Entity field required when creating a contract. How can that be done for Procurement contracts?

Content (required):

We tried to see if this could be accomplished via Page Composer but we couldn't open the Create Contract task from the Task Panel in order to edit the properties for the Legal Entity field.

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

22B

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