Is my translation correct?

日本に一番高い建物は何ですか

Asking because both chat gpt are saying to use で instead of に, which i dont think is correct for two reasons. There is no verb taking place and NI is used in where things exist.
A way i was explained is Ni defines the location where someone or something is. De defines the location where someone does something
日本で一番高い建物は何ですか

Thanks,

This is one of those topics, like almost all of them, where you find the basic rules you learned don't cover all the subtleties. These are both correct with subtle differences in meaning that I don't think make much difference in this case. If I explain it, I'll probably be wrong so we should wait for the experts. But I'll say, that I would normally add a silent (は) to help tease the difference in meaning.
日本に(は)一番高い建物は何ですか
Here we get IN Japan.
日本で(は)一番高い建物は何ですか
Here we get As for Japan.

This example is difficult to differentiate but consider
東京に(は)一番美味しいレストランは何ですか
Here, I feel like the question is what is the best restaurant IN Tokyo (within its boundaries).
東京で(は)一番美味しいレストランは何ですか
Whereas here, I feel like the answer could be some place on the other side of the Edo River that's technically in Chiba but close enough to say Tokyo.

But I could be totally off base here. Let's see what the experts say.

Treesgotowar said:

日本に一番高い建物は何ですか

Asking because both chat gpt are saying to use で instead of に, which i dont think is correct for two reasons. There is no verb taking place and NI is used in where things exist.
A way i was explained is Ni defines the location where someone or something is. De defines the location where someone does something
日本で一番高い建物は何ですか

Thanks,

Click to expand...

To indicate the location of action is just one of many functions of で. で indicates "extent" there. It can be used both for spatial area and temporal period.
e.g.
アメリカで一番狭い州はどこですか。
あの喫茶店のコーヒーは、近所で一番安くて美味しいです。
戦国時代で一番強い武将は誰ですか。
今年の夏は今までで一番暑いです。
あなたと過ごした日は二十世紀で最高の出来事 (from a song lyrics)

で の解説
４ 期限・限度・基準を表す。「一日―仕上げる」「五つ―二〇〇円」

Click to expand...

Indeed に is used to indicate the location of existence, but it's when with a verb of existence.
e.g.
日本にある一番高い建物は何ですか。
＝日本にある建物で、一番高いのは何ですか。
(Needless to say, this で indicates "extent".)