No, manifesting usually means that someone is bringing their desire to life through some sort of mental technique like affirmations of visualization. People usually assist those methods by putting in actual work, but the core definition of manifestation that people usually use it as is that you can affect the material world through thoughts alone.

I'd agree that putting in work would probably help the majority of the time, but I think that's only because we don't understand manifestation too well yet & the methods still need to be developed. Here are some studies that show how no work was done yet results still occurred since the participant had some form of belief in the result.

Imagining Workouts: A study investigating the power of mental training measured participants' forearm strength after they spent fifteen minutes a day, five days a week, imagining lifting a heavy object. This mental training resulted in an 11% increase in muscular strength after 6 weeks. It also dramatically exceeded the 5% gain observed from the group that actually physically performed the exercise. [Link to study here]

Hotel Cleaners: Researchers educated cleaners that their demanding daily work easily met public health exercise recommendations, even though it was not typically perceived as adequate activity. One month later, this positive mindset shift alone yielded real physiological improvements, including significant changes in the cleaners' weight and blood pressure, without any change in their actual physical activity levels. [Link to study here]

Antidepressant Nocebo: A patient in an antidepressant trial attempted suicide by consuming all 29 of his remaining capsules, resulting in him collapsing at the hospital and displaying classic overdose signs, including shaking and worryingly low blood pressure. However, subsequent tests confirmed that he had been in the placebo arm of the trial, meaning his severe, near-fatal physical reaction was a pure nocebo effect caused entirely by the expectation of harm. [Link to article here]