Translation:Have the engineers bought the insurance yet?
The presence or absence of the article affects the meaning in English. "The" refers to some particular insurance that the engineers are expected to buy. No "the" simply asks whether the engineers bought insurance from any source. I have no trouble with the idea that the Vietnamese can mean either but it would be nice to know which meaning a native Vietnamese speaker would opt for.
I would have meant any insurance, the source does not matter, as I just want to know they have any. if I were to mean a specific insurance, I would use này, đó, kia, or any other way like the source "bảo hiểm X bán" (the insurance sold by X); the kind: "bảo hiểm nhân thọ" (life insurance, for example); etc.