Problem with Ngui for the package "NJG Mini / World Map" Unity Store

Hi, I have problem with Ngui for the package “NJG Mini / World Map” Unity Store.

I bought “NJG Mini / World Map” Unity in store. I downloaded and added the package,
But the watermark “Ngui (NEXT-GEN UI)” and the text “Created using free version …” are appearing.

Even after importing the package “ngui_distribution_unity4.unitypackage” watermark “Ngui (NEXT-GEN UI)” and the text “Created using free version …” keep appearing. Care also “ngui_free.unitypackage” but the problem continues.

How can I remove the watermark “Ngui (NEXT-GEN UI)”?
And the text “Created using free version …”? How to remove?
I import some specific package so that the watermark does not appear?
What are the steps to remove the watermark?

I am using free version!