Unlike the regular MagicBands, MagicBand+ must be charged for use. It comes with a charger and USB cord.
To charge the MagicBand+, snap the band into the charger with the Mickey icon in the center. The band will likely need to be charged after purchase (and possibly even several times a day — we recommend bringing a portable battery charger, especially if you want to play Batuu Bounty Hunters).
On the back, you can see where the charger will match up with the band.