@matti Does Napu have a crate? Initially I was opposed because I didn't understand their use, but it turned out to be a great thing. https://www.amazon.com/s?k=soft+dog+crate

The soft crate we bought was much better than the wire crate we had. This can become a totally safe space for a dog. Never used a punishment. Use treats etc to establish it as the dog's own safe comfortable place. Once the dog is completely comfortable (may be weeks) start by zipping her in and get used to that. Then maybe leave the room for a minute. Work up to leaving for sensible amounts of time.