Is Two-Step Verification Required to Use the ECG App on My Watch?

Yes, permanent two-step account verification is required on your Garmin Connect™ account when the ECG app is enabled. As this is permanent it will continue to be required on your account even if you disable the ECG application. 

Can I Change the Method of Delivery for the Verification Code?

Yes, you can use either email or text. For more information about the two-step account verification including steps to change the method of delivery see: Two-Step Verification on Garmin Accounts