@蘇楚淵 Have you created a custom search resource from azure portal and is that key used in this screen? We use the custom search resource key in this field to get a custom search auto suggest call. For ex:
With the auto suggest resource key that you are using you can try this call to check if it works fine.
curl -H "Ocp-Apim-Subscription-Key: <yourkeygoeshere>" https://api.bing.microsoft.com/v7.0/suggestions?q=sail
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