Hello Saima,
Please provide more information about your environment and what you are trying to do. For example, how are you using the API? From the screenshot you posted, it looks like you're using a Stardog-provided Java client library for version 8.2.2, is that correct? Are you able to make other calls successfully and only this one is failing, or are all your API calls to your Stardog server failing? What specific call are you making (it looks like a query, but the more details you provide, the better)? Are you able to access your Stardog server using the Stardog Cloud web UI (e.g., using Stardog Studio)? If so, are you using the same credentials for your API calls?