I just added Marketing API to my Facebook app to retrieve leads from a leadgen form. In the Marketing API Settings section it says: Ads API Access Level: development and in details it says App doesn't have Ads Management Standard Access. However, on permissions section it says that I already have standard access to Ads Management Standard. Any help would be highly appreciated.

You need to request advanced access for Ads Management Standard Access and submit your Facebook app for review.
Once approved, your Ads API Access Level should automatically change to "standard".
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