Hi! I understand you're having trouble with the KS Fit app not showing your heart rate. Let's work together to get this sorted out.

First, could you tell me a bit more about your setup? For example:
- Are you using a device like an Apple Watch or a chest strap to measure your heart rate?
- Have you granted the KS Fit app permission to access your heart rate data on your iPhone?
- Is your heart rate sensor connected and working with other apps?

Meanwhile, here is a step-by-step guide to try:

1. Check Permissions: On your iPhone (iOS 18.7), go to Settings > Privacy & Security > Health and make sure KS Fit app has permission to access your heart rate data.

2. Connect Heart Rate Device: If you use an Apple Watch or a heart rate monitor, ensure it’s paired and connected to your iPhone properly via Bluetooth.

3. Sync with Health App: KS Fit may rely on the Apple Health app to obtain heart rate data. Open the Health app and verify that your heart rate readings are being recorded there.

4. Restart the App & Device: Close KS Fit completely and restart your iPhone to refresh connections.

5. Update the App: Make sure your KS Fit app is updated to the latest version from the App Store to avoid known bugs.

6. Check Device Compatibility: Some users have reported issues where KS Fit shows zero heart rate because it reads data actively from an Apple Watch app. So if you’re not using the Apple Watch app version of KS Fit or the watch itself, heart rate might not show1.

Let me know what you observe from these checks. If heart rate data still does not display after this, we can explore advanced settings or look for any software updates needed on your treadmill or fitness device.

Are you able to try these steps and tell me what happens?