How the nightlight that found favour was spoken of? (9)

I believe the answer is:

glowingly

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'how' is the definition.
Both the answer and definition are adverbs. Perhaps they are linked in a way I don't understand?

I can't explain the remainder of the clue.

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(Other definitions for glowingly that I've seen before include "How Lampyris noctiluca shines" , "with great enthusiasm!" .)

I've seen this clue in the Evening Standard.

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