To be honest for us to be able to help you, you’d have to show us the whole API call. Sure, the Array you showed us may be correct depending on the context. If I were you, I would copy the whole body and stick it here:
This is a JSON validator. If there is a syntax error in your body, then it will throw an error.
You’re putting your Keys inside the parameters section, this is not where it’s supposed to go for POST calls. The body of your API call needs to go in the Body section in the API connector (the text box that says Body (JSON Object, use <> for dynamic values)).