Hi Thomas,
Could you please confirm if you're referring to Change History in the Google Ads account? If so, this will usually display the email address of the user authenticating the API call and making the changes in the Google Ads account. If you are looking to change the email address, you will need to generate OAuth credentials using this address (a...@digiscale.com) and authorize to make the API call.
Let me know if you have any other questions.
Regards,
Bharani, Google Ads API Team