"Saya bukan dari Jepang."

Translation: I am not from Japan.

[MaxLegault1]

Why not tidak here?

[Jacob334071]

To sum up something I read about this:

Tidak == No

Bukan == Not

[PERCE_NEIGE]

Tidak is "don't" for verbs, as used to negate verbs.

Saya tidak makan = I don't eat.

Bukan is used to negate nouns, (or a preposition like here).
If there's a verb, use tidak.

The verb is implied here in Indonesian, so, no "tidak".
Saya dari Jepang, litterally" I from Japan", "to be" is only implied here.

[JimSteel3]

The word am was not in the list to choose.

[PERCE_NEIGE]

Please read my comment above. Most of the time, the verb "to be" is implied in Indonesian. So "I from Japan" means "I am from Japan".