For your bets to count towards a challenge, you must follow these steps:
Go to the Missions section.
Choose your desired mission and click "Learn More" to read the requirements.
Important: Click the "Join/Participate" button. If you do not click this button before betting, your bet will not count towards the mission.
Place your bets according to the mission rules (Minimum Odds, specific markets, etc.).
Track your progress through the progress bar visible within the mission itself.