Failed when querying Provider REST API

We are integrating messaging inbox.
After creating channel with POST /v1/channels the channel creates successfully, but we get an generic error
“success”: false,
“error”: “Failed when querying Provider REST API”,
“error_info”: “Please check the reference docs in Pipedrive API v1 Reference”,
“additional_data”: {
But in getConversations (from manifest.json) returns a response as described here

Hey, I have just sent you a message with details.