Hello,   We have to migrate to v3 because some functionalities are retired on v2 and that made our current transaction email process fail. Our process doesn't involve end users, we are sending emails directly to them thru cc based on rules.   On v2 we were use to connect with api key has a get parameter and use Authorization Bearer to call APIs to create contact, list, campaigns, etc... I cannot access v3 API with the new authentication mechanism. I don't have the use of the redirect url to ask user permission as the process is server to server. Do we have a way/document that explain how to directly interact with v3 APIs using client_id and secret? I have contacted support by phone and by email but for the moment I am still blocked.   Thanks for your help ... View more