@AI_stud Thanks for the question, Can you please add more details about the key that you are using, is it from marketplace www.microsoft.com/en-us/bing/apis or https://azure.microsoft.com/en-us/services/cognitive-services. We have forwarded to the product team for using client library error to check.
If the resource created using marketplace please use REST API and follow the below documentation for Bing image search.
https://learn.microsoft.com/en-us/bing/search-apis/bing-image-search/samples