"Anda menunjukkan kepada mereka."
Terjemahan:You show them.
"You show them" is better in English, but now "You show to them" is also accepted by this app.
Often, we cannot translate languages literally because languages have different grammars. We use 'to' after 'show' only with S V O sentences:
I showed my birthday present to my friend. She showed her dancing skills to the judges. The scientists showed the results to the President.
In S V IO O sentences, the preposition is not used: I showed my friend my birthday present. She showed the judges her dancing skills. The scientists showed the President the results.