hello,
my cat did this when she was a kitten, we tried to encourage her to use the tray, the best thing we found is putting the tray where she was preferring to go. It got to the point where we had a tray in every corner of our lounge! She then got used to using the tray and we began to remove one tray at a time until there was just one left that she used. now she's bigger she goes outside and we don't have a tray anymore, we found it was the only way to save our carpet, it took a few weeks to do, but it was worth it.

hope this helps
x

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I had been told that the training procedure with cats was difficult. It's not. Mine had me trained in two days.