You can track all of your bets on the website just like you would on the mobile app. Click on your preferred wager on the odds page, and confirm the bet on the pop-up on the right side of the page.
Once you click on a pick, you will see the BetSlip pop up from the top of the page. From here you can adjust the odds, amount risked, and add notes. After adjusting your pick you can then select the 'Track Bets' option at the bottom to save your pick(s).
Any bets you make on the website will show up in your 'My Action' tab on the app and vice versa.