4 Answers

Train your dog exactly as you did to go outside rather than in.  It is safe but keep that litter box clean.

Oh My - Are you serious - no matter what the breed of dog  - they can all be trained to use a liiter box, as for  myself I would prefer to take them for a walk all beit a walk in the garden - best just a walk in the park -  I know nothing ot a litter tray being dangerous - what are you using? . Good LUCK. Do you know I feel such a prat to even answer your question as often so obvious.   

As Fish girl has said train as you would out side but make sure you keep on top in the cleaning of it good luck

Yes . I have friend that has yorkies and they do fine using a litter box.