This is the 19323rd most frequent Korean word.
알려주지
"알려주지" means "let (someone) know" or "inform."
In this sentence, '알려주지' is used as part of '알려주지 않았다', which means 'did not let (someone) know', in the negative past tense.
그녀는 나에게 비밀을 알려주지 않았다.
She did not let me know her secret.
Here, '알려주지' serves in ‘알려주지 않을 거야’, implying an intention to not inform someone, in the negative future tense.
새로운 소식을 알려주지 않을 거야.
I will not inform you of the new update.
In this case, '알려주지' is used affirmatively with the implication of providing information or making someone aware, under the condition specified.