Is there any legal problems to create PNG picture from SFSymbols?

I want to create PNG from SFsymbols so that support versions less than iOS12. I'm not going to process the looks, just to convert to PNG.
So I want to know if there is a conflict apples rights.
I already asked to developer support. but they could not discover information about it too.
I appreciate you in advance for your thinking for this question what written in poor English.
Is there any legal problems to create PNG picture from SFSymbols?
 
 
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