Answer
Meters shipped after January 2021 come with a random password assigned to the meter at the time of manufacture. This password is printed on the side of the meter opposite the CT ports. Assuming the meter still has the default eGauge configuration, refer to the label affixed to the eGauge to locate the default login credentials:

- eGauge Systems does not maintain a record of the password associated with a meter. A remote password reset can be performed through eGuard, but the original password cannot be restored.
- Note that a factory reset will restore the password the meter originally came with, but will also reset all of the meter setting as they were out of the box.
Meters purchased prior to Jan 2021:
Assuming the device comes with the default eGauge configuration, you may use the following credentials to make changes:
user: owner
password: default
In order to use these credentials, you must ensure that you are directly connected to the device by clicking the LAN Access link at the top right of the device web page before entering credentials. When done correctly, the address in your browser address bar will change from a full URL (for example, http://DEVNAME.egaug.es) to an IP address (for example, 192.168.1.88).
See this article if you're having trouble remembering your password.