apple-watch
Recently, Apple launched ECG Feature for India quite recently with the latest generation of WatchOS. I do not seem to have it on my Apple Watch Series 4 even after updating it to the latest version of WatchOS.
How do I go about troubleshooting to get the ECG app?
iPhone is on the latest version of iOS.
Apple Website – https://www.apple.com/in/watchos/feature-availability/#branded-ecg
On your iPhone, go to settings, general, date/time. Disable auto time zone and switch to another time zone. Then switch back to your own time zone (maybe wait a bit for the watch to pick up the change?). It will ask you again.
I went for a 2:30:00 run yesterday with my iPhone (6s) in my bag and my watch running strava. VO2max was recorded once per hour in three hours (10-11/11-12/12-13). I’ve tried to get VO2max off of shorter runs (5k-10k) on the same route without my phone but no data. I will now have to test longer runs with just watch and shorter ones with phone to get a definitive answer. Hope this is helpful. 
Best Answer
Make sure that you also update your iPhone to the latest version of iOS as well. The ECG feature is on the iPhone and it needs to be enabled there 1st.
Set up the ECG app
https://support.apple.com/en-us/HT208955