Constant contact API doesn't work as expected

[EricB3781]

Hi. I'm trying to use Constant Contact API and I'm having issue which says the following: {"error_key": "http.status.internal_server_error", "error_message": "We are currently experiencing an issue with our service, please try again in a few minutes or contact Customer Support." }

Here is the screenshot 


Can you please check that? I need to have API working
Thanks in advance