を探すのを手伝って

help me look for …

→ を
phrase Rare #38,797
help me look for … The を marks the thing being searched for. In this plain form, 手伝って is a casual request; adding ください makes it more polite.
JA: スマホを探すのを手伝ってください。
EN: Please help me look for my phone.

財布を探すのを手伝ってくれませんか。

Could you help me look for my wallet?

彼らを探すのを手伝ってもらえる?

Could you help me look for them?