@vladobet11, you’re getting the stats endpoint confused with the actual retrieval endpoint.
GET accounts/%3Aaccount_id/promoted_tweets gets you the Promoted Tweets associated with your accounts. If you provide a line_item_id, it provides you with a list of promoted_tweets and their ids for that line item.
Now you take those promoted tweet ids (as entity_ids) and use the single stats end point to get your data for your promoted tweets.
"request": {
"params": {
"start_time": "2016-02-01T15:00:00Z",
"entity_ids": "43gk6",
"end_time": "2016-02-01T17:00:00Z",
"placement": "ALL_ON_TWITTER",
"granularity": "HOUR",
"entity": "PROMOTED_TWEET",
"metric_groups": [
"BILLING"
]
}
}