AI Image upscaling is a Pro feature. It is not fully integrated in Nero Platinum Suite product. So there is always a Nero log in right bottom corner. (The trial version is full of Nero logo). 

To activate the Pro feature without Nero logo, we have released Nero AI Image Upscaler subscription in Windows store:

In Nero Suite Platinum you can manually add a blank border below the image and manually crop the logo after upscaling.