The -ing forms

Hi everyone.

First of all, english is not my native language.

I have a question about the -ing forms.

Especially in combination with "Let it ..."

If I check internet entries I can find sentences with "Let it running"

But if I check "Let it" with other -ing combinations like "Let it burning" or "Let it going" or "Let it rolling" or "Let it flowing", I don't find that many entries. Nearly nothing.

I know, normally you say: "Let it burn" "Let it go" or "Let it roll" but also "Let it run" without -ing.

So is this really completely wrong if I say something like "Hey, let it burning" or "Let it flowing"?

Or is this allowed in some situations? Also if I know that "let it burn" the right sentence is?

Thanks for you help.