Extending the Next Generation Self-Service Supplier Registration - Error getting dfd lov values

Summary:

When clicking on dfd flex's lov, "Supplier registration" is not able to show any lov's value

Doing inspect on htm, i get "Unauthorized" error. This is only happening when accessing by "supplier registration"'s external link.

Please, appreciate someone to guide me about permissions required

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

25A