I don't see the ecg or ekg app in the store or on my phone.

For the ECG app to work on your watch the ECG app has to be approved by;

A. the government of the country in which the watch was bought and

B.the government of the country in which you reside.

Countries that support ECG app

First, make sure that your Apple ID, Apple Watch, iPhone, and you yourself, are in an area that allows the ECG app. Check here: https://www.apple.com/watchos/feature-availability/#branded-ecg

If you are in an area that supports the ECG app, then follow the steps below.

Set up the ECG app

1. Open the Health app on your iPhone. 
2. Follow the onscreen steps. If you don't see a prompt to set up, tap the Browse tab, then tap Heart > Electrocardiograms (ECG) > Set Up ECG App. 
3. After you complete set up, open the ECG app  to take an ECG.

If you still don’t see the app on your Apple Watch, you can search the App Store on your Apple Watch for ECG and download it.

ECG app is only available for apple watch 4 and 5.