Did you check the response after running the request? You can right-click the module and select ‘Run this module only’, and then see what the response states.
Also, I see that the linked document ‘Ad Creative specification’ doesn’t have a reference of the JSON format, so it’d probably be best to convert the cURL example to JSON so you have the correct schema & properties. There are online tools to do this conversion
You could also first get an existing Ad from your account, then use that response as the base to create the correct payload for creating an ad.
And, whenever you’re creating a JSON payload it’s always best to validate that it’s correct too.
There might be errors in your JSON, as I see numbers sent as strings “12345”.
But! This depends on the property spec, so best to clarify that first
And to make sure I am putting the right JSON format,
I checked my JSON string using Meta for Developers > Graph API explorer.
When I use Graph API ‘POST’ function, the same JSON string works properly.