Toca boca can you merge two different electronics with different Apple ID

Lets say you had an ipad and a iphone and you downloaded Toca boca on your ipad first and made purchases on it and then you downloaded on your iPhone and maid more purchases on your iPhone, but now u want to mege it in all in one device. How can u merge it if u can? And if you can’t is there any way you can get your money back to buy it all in one device?