Notification says insufficient funds, contribution will be held in next month

@RahatKhalique first, that’s not how you earn rewards (BAT). Brave Rewards is consist of two features:

  • Auto-contribute and Tipping – a feature that allow Brave users to support publisher and creators,
  • and Brave Ads – a feature that allow Brave users to earn BAT; available for supported countries. FAQ: Why am I not seeing Brave Ads?

More https://support.brave.com/hc/en-us/sections/360003095931-Rewards and https://support.brave.com/hc/en-us/sections/360004119132-Brave-Ads