How to prevent user from submitting a requisition if no mapping set has been defined?

Summary:

Mapping set has not been configured for certain business units in the configuration 'Manage Mapping Sets'.

Is there a workaround to prevent users from submitting the purchase requisition or trigger an error message

when a mapping set is missing?

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

25A

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