If you find that your Health Kit button is disabled or not responding, this is working as intended!
Please check your equipped booster cards. You likely have the Madness booster card equipped.
Madness Ability: Increases your damage by 50%, but prevents you from using Health Kits for the duration of its effect.
If you wish to use Health Kits during your matches, simply unequip or swap out the Madness card before entering the game! 💀