Saving a magnolia grandiflora?

First post!
We recently moved to a new house and garden in Comox which included a magnolia grandiflora. It looks a bit sickly though (few leaves, the ones it does have are yellowish)

It’s on the northwest side of our house and relatively protected by our neighbours house/deck.

Curious whether I can prune it? The internet is giving conflicting advice. Any advice appreciated.

Thank you.
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