Get a baby gate, put it on the bathroom door,
make sure you set up a bed for the puppy and toys,
only do this after feeding the puppy,
leave the puppy in the bathroom with the gate
spray the potty park with potty spray
This are the cheapest I can find “links” they may no longer be listed to sale on ebay but you can veiw them and look on ebay for the current ads.
Then leave the puppy in there up to 2 hours after feedings, till they go to the bathroom.
when they do, give them a few licks of vanilla ice cream, only give them the vanilla ice cream for rewards, so they know if they want ice cream they need to earn it.
after they go potty the gate can be opened, but if they potty in another area, they need to be put back in the bathroom till they go on the potty park and get the ice cream.
NEVER YELL OR HIT A DOG!
A dogs logic dose not understand punishment, so they will ether become withdrawn or guarded.