How to edit or remove the button "Rights of use"

Hello,

I'm using the "Fill in the blanks" content type. When I publish the exercise, I see below a button called "Rights of use".If I click on it, I can read a message on a pop-up saying "Rights of use. No copyright information available for this content". (as seen in the attachment).

I would like to know where I can edit this message, and on the other hand how can I remove this button "Rights of use".

Thank you very much and congratulations for your work!

Daniel.