Is it possible to enable ecg

I believe the Watch needs to be purchased in a country/region in which the ECG app is currently available. Changing the Apple ID or the Region in Settings wouldn't make a difference.

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.

There is no workaround.