In indonesia, we don't use she,he. We just called it "dia" so it can referred to she or he
No it can't because,
1) Singular they is not accepted grammar in English even though it is commonly used.
2) They is translated as Mereka in Bahasa Indonesia.
Can't 'they' also be translated as the gender-neutral alternative pronoun to 'he' and 'she', regardless of whether the subject is singular or plural?
According to accepted English grammar they is a third person plural pronoun. It is not considered singular. This means that Mereka is the only possible translation for they in Bahasa Indonesia.
The word Dia is a third person singular pronoun that is also gender neutral. There is no equivalent in accepted English grammar, she has traditionally been used to fill this gap.
When translating foreign languages the convention is to stick to the accepted grammar of each language.
It's also worth mentioning that using they as gender neutral substitute for he/she in English is still currently being debated by the grammar community.
I could swear I wrote this correctly about six times, but it kept telling me I was wrong...
I wrote "She is lives in Jakarta, not Bali." but it was meant to be "is from"