Hello there,
hope you all are doing well! ??
Sorry for the late reply.
No action should be required, since Authorize.net will be adding domains they see used on merchants for the month of June 2019 to their accounts settings to help prevent any issues with this update.
Anyway, the domain where you are using the Authorize.net plugin should be fine
as they said “As a part of this change we will be changing the check of the full URL to just the domain is matching with any Relay Response URL(s) passed in the API call”
So, you will need to check the whitelisted domains, Authorize.net will be adding the ones they see active and if for any reason your domain is not in the whitelisted ones, you will need to add it.
You can find additional information here:
https://support.authorize.net/s/article/SIM-Relay-Response-Basics
https://support.authorize.net/s/article/How-do-I-add-or-delete-Relay-or-Response-URLs
If you have any doubt let us know and we will be happy to help you.
Have a nice day!