I have a development level access to Marketing API and it looks like I cannot read some fields of specific objects.
For example I try the following call:
You can see that promoted_object, link_url and object_url are not displayed in the result. And I should have one of those three value as the Ads was ad to promote "web site click".
Is it a bug or a limitation of the development acces or I am doing something wrong?
It is true that not all fields are readable by all apps, however in the case above it is most likely that these fields are empty on that object and therefore not returned in the response.
Promoted object, for example, is required on the adset level now, however it may be the case the adset you are trying to read is very old and therefore does not have one specified.
In regards to the creative fields, again not all creatives have these fields and in the case they are empty, are not returned in the response. You should check the promoted_story_id to see if this contains what you're looking for.