Fitbit API: Not returning the steps for a time range on a date

I am using the Fitbit endpoint in iOS app to fetch the steps as below:

https://api.fitbit.com/1/user/-/activities/steps/date/2019-07-01/1d/15min/time/12:00/12:15.json

This is to fetch the steps on a date for some time interval but it returns the array of some activities like Yoga, Walking, Winter activities etc. but not returning the steps count for the time interval. Can anyone please tell me how can I fetch the data for the same?

It returns the result as:

"categories": [
    {
        "activities": [
            {
                "accessLevel": "PUBLIC",
                "activityLevels": [
                    {
                        "id": 3016,
                        "maxSpeedMPH": -1,
                        "mets": 8.5,
                        "minSpeedMPH": -1,
                        "name": "6 - 8 inch step"
                    },
                    {
                        "id": 3017,
                        "maxSpeedMPH": -1,
                        "mets": 10,
                        "minSpeedMPH": -1,
                        "name": "10 - 12 inch step"
                    }
                ],
                "hasSpeed": false,
                "id": 90004,
                "name": "Aerobic step"
            },
            {
                "accessLevel": "PUBLIC",
                "hasSpeed": false,
                "id": 3015,
                "mets": 6.5,
                "name": "Aerobic, general"
            },

I found the reason behind Fitbit returning such data. It is just because the intraday data fetch requires the review from Fitbit or we can use the "personal" application type to get the data.