Where can I find the username or identifier associated with the API key?

On the N8N platform, under Header Parameters, I need to verify myself by entering a username and API key.
I have received the API key from the OCR website, but I’m not sure where to find the username (or ID) that needs to be used along with the key.
Could you please tell me where I can find it?

The OCR API does not have any user name, only the api key, which you should add to the header section of the api call: