When your contest balance drops below $1,000, the "Buy Credit" button will appear at the top of your trading room. To recharge your balance, simply click on the button. This will open a menu where you can select your desired recharge amount: $10,000 for $5 or $5,000 for $3. After selecting the option that fits your needs, confirm your choice by clicking the "Apply" button. The payment will be deducted directly from your real balance, allowing you to continue participating in the contest.