Focus Sash
This goal requires you to obtain an Focus Sash.
It is given to you as a Battle League reward for defeating four trainers in West Province (Area Two).
Alternatively, the Focus Sash is available for purchase at Delibird Presents for ₽50,000 as soon as you have collected four Gym Badges.
Location
Section titled “Location”The Battle League Rep that gives you this reward is located at the PokéCenter near the West Lighthouse.