直接 and 直ちに: directly and immediately
Distinguish acting without an intermediary from acting without delay.
A method without an intermediary
直接 is read ちょくせつ and refers to acting without an intermediate person or step. 「本人に直接聞きました」 means that the speaker asked the person concerned directly.
「店に直接電話してください」 asks someone to call the store directly. 直接 does not necessarily mean face-to-face contact.
Acting without delay
直ちに is read ただちに and means acting immediately without delay. 「直ちに作業を中止してください」 instructs someone to stop work immediately.
It often appears in notices or instructions requiring an urgent response. The key is when to act, not whether someone passes information through an intermediary.
Two independent conditions
「明日、本人に直接伝えます」 says that the speaker will tell the person concerned directly tomorrow. Direct communication need not happen immediately.
「担当者を通して直ちに連絡します」 says that contact will be made immediately through the person in charge. An intermediary can be involved without delay, so the two words are not interchangeable.
Does 「直接連絡してください」 necessarily require contact right now?
Show the answer and why
No. It requests direct contact without an intermediary. To require immediate action, state the timing separately, as in 「直ちに連絡してください」.