@tom_31037 The spell check API is available. You need to create the bing search resource by searching for "bing search" and create a resource.
You can use this API endpoint for all offerings of bing web search API's and only the endpoint changes for these offerings where the base API is "https://api.bing.microsoft.com/v7.0/"
and for spell check you only need to append SpellCheck to the endpoint to make it "https://api.bing.microsoft.com/v7.0/SpellCheck"