Apparently the wet renal is not the tastiest feline gourmet experience

Best to introduce it by mixing it with current food in ever increasing percentages.

Or add some tuna or salmon juice from a tin of your own/their food.

Cleo wouldn't touch it a year ago, now she is happy to hoe into it with gusto I don't give it to her at every meal but I mix it 1/2 and 1/2 or give it to her as an additional meal in the day if she asks for food.