How to monitor ekg in my smart watch

Perhaps this article will help:

Taking an ECG with the ECG app on Apple Watch Series 4 or later - Apple Support

and also note that the ECG app is currently available only in certain countries and regions. Learn where the ECG app is available.

Look under the health app on your phone they are stored there. Then you can send them to your doctor that way.

ECG is for apple watch 4 and 5 only.