Hi,
Thanks for reaching out to us. The main page of Bing Spell Check API and the document of it has been updated. The testing console has been removed. https://www.microsoft.com/en-us/bing/apis/bing-spell-check-api
I will forward your feedback to document team to see how we can better help customer to try. Now I will highly recommend you to easily click "try it " and follow the quickstart : https://video2.skills-academy.com/en-us/bing/search-apis/bing-spell-check/quickstarts/quickstarts
Regards,
Yutong