[Grammar] need help (doing/in dong/to do)?

preachers said:

I've learned the usage of the word "need". When using with subject of person, it follows by a infinitive. If the subject is a stuff, then it follows by a gerund. [That's ungrammatical and doesn't make much sense.]

somebody + need + to do
something + need + doing

But when it comes to "need help + verb" like the title described, which one is right, and why?

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preachers said:

Thanks for your/the quick reply!

The whole sentence is here "Now that we're all on the same page, enable USB debugging on your device (see your device's manual if you need help finding it, and remember it was hidden in Android 4.2), and plug it in to your computer."

If the sentence is right, dose it conflict with this one (somebody + need + to do)? or can I say it like "if you need help in finding it" or "if you need help to find it"? Why?

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