Displaying a detail of Custom package in Contacts Section

Hi Community,

I have created a custom package [Certification] and have changed the prefix for Object Name to [Test].

Inside the Certification package I have created a Returns section. Now I need to customize the Contacts section of [Custom] package by adding a Return Requests detail in Returns tab. 

I tried creating this new detail in the Returns tab in Contacts section, but the changes are not reflected even after making the required changes in the configuration.

Sharing the screenshot for reference.

Thanks in advance!!

Dolly