You can add a CC or BCC to any template like this:
- Navigate to "E-mails" and then the Configuration Tab
- Select your desired E-mail by pressing "Default template" (In your case most likely "Completion E-mail")
- Press on Edit
- Now under Email Details you should see Carbon Copy (CC) and Blind Carbon Copy (BCC).
Here you can add your desired E-mail address.
I hope I was helpful. If you want us to look into this with more detail please send us an E-mail to email@example.com.