facebook marketing API Unable to create adset with targeting

need some help i'm trying to create an adset with cities in the targeting object but i'm getting an error

{     "error": {         "message": "Invalid parameter",         "type": "OAuthException",         "code": 100,         "error_data": "{\"blame_field\":\"targeting\"}",         "error_subcode": 1487756,         "is_transient": false,         "error_user_title": "Locations can't be used",         "error_user_msg": "Some of your locations overlap. Try removing a location.",         "fbtrace_id": "AApf6HmHZneXVFLD1U8BK-D"     } } 

steps to reproduce 1- create a campaign

curl -X POST https://graph.facebook.com/$API_VERSION/$ACCOUNT_ID/campaigns -F 'name=My Campaign' \    -F 'objective=OUTCOME_AWARENESS'\    -F 'status=PAUSED' \ -F 'special_ad_categories=[]'\    -F "access_token=$ACCESS_TOKEN" 

then, create an adset for this campaign

curl -X POST https://graph.facebook.com/v21.0/$MY_META_ACCOUNT_ID/adsets \   -F 'name=My Ad Set' \   -F 'campaign_id=6680088172618' \   -F 'daily_budget=1000' \   -F 'targeting={"geo_locations":{"countries":["US"],"cities":[{"key":2427178}]}}' \   -F "access_token=$MY_META_ACCESS_TOKEN" \ -F "billing_event=IMPRESSIONS"