You can purchase medkits to speed up your experience gain in the national progression system. For the duration of a medkit, you will receive double XP.
To buy a medkit, select your player name on the top left of the screen and navigate to the “Rewards” tab. Click the “Medkits” button in the top-right corner of this interface.
Select the medkit you would like to purchase. You can select a 1-day, 3-day, or 7-day medkit.
Click on the “buy” button for the desired medkit to purchase the medkit in question. Once a medkit has been purchased you can click the “Activate” button in that same interface to start using the medkit and get double XP for the duration of the medkit.
You can see the remaining duration of your medkit next to the national progression bar on the home screen.
Note that an active medkit does not pause or stop while you are not playing KARDS.