Not sure where you got that API syntax from, but there are specific REST endpoints that will return the value(s) for a capability. For example, for a dimmer that supports these capabilities:
───────────────────
Attribute Value
levelRange
level 1 %
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I am using the ST CLI in DEBUG mode to show the API calls the CLI makes to get data or execute commands. I would suggest using the CLI to determine the specific API call required to retrieve the value you are interested in. Also, no Body was required for this API call, only the Auth Header.
You can also “smartthings devices:capability-status” which will allow you to select a device and then give you a list of its capabilities similar to what is in my first post.
The other option if you aren’t comfortable with the CLI is to use the ST Advanced Web App which will give you a list of the capabilities in the Attributes section of the device info.
I’ve been testing for days, and unfortunately, none of the available capabilities seem to be responsible for the display. I’ve seen other cases where ‘samsungce.airConditionerLighting’ was the correct option, but this capability is not available in my case.