From the Home page in the mobile app, tap the Schedule icon. This will put you on the middle screen in the image below.
Scroll to the current date. Note that the current date will always show up as the lighter date between the darker (in the past) and mid-tone (in the future) dates. Note that future dates may describe the workout as TBA ("To Be Announced"). This is at the discretion of the particular gym. Note also that only the present and past dates have a score section.
Tap the pencil & pad icon to open the Save Score screen.
Select the scale with which you performed the workout. Either RX, B, C or Masters.
Enter your time or reps or weight or duration, etc. The scoring method will reflect the particular workout.
Enter any notes about your workout (e.g. what made it scale B).
Click the save icon in the top-right.
Your score will now show up on the schedule and on the leaderboard