Get spot instance cost by costExplorer get-cost-and-usage cli

I created a spot instance, and after a day, I use costExplorer get-cost-and-usage to get real cost of this instance. But I got the cost is the same with on demand pricing.

I'm starting to doubt my instance is spot or not. I can see my instance "Lifecycle" is "Spot" in ec2 console. And I can see this instance in "Spot Requests" list.

If we confirm the instance is spot, so my question is whether costExplorer api can get spot instance cost and how to get it?

Thanks, Mingtong