Request token retrieval failed:

RESPONSE:

Array
(
    [linkedin] => Array
        (
        )

    [info] => Array
        (
            [url] => https://api.linkedin.com/uas/oauth/requestToken
            [content_type] => 
            [http_code] => 0
            [header_size] => 0
            [request_size] => 0
            [filetime] => -1
            [ssl_verify_result] => 0
            [redirect_count] => 0
            [total_time] => 0.015355
            [namelookup_time] => 0.002127
            [connect_time] => 0.01538
            [pretransfer_time] => 0
            [size_upload] => 0
            [size_download] => 0
            [speed_download] => 0
            [speed_upload] => 0
            [download_content_length] => -1
            [upload_content_length] => -1
            [starttransfer_time] => 0
            [redirect_time] => 0
        )

    [oauth] => Array
        (
            [header] => Authorization: OAuth realm="http%3A%2F%2Fapi.linkedin.com",oauth_version="1.0",oauth_nonce="46e3489d3a270b4d045f9550dc55d967",oauth_timestamp="1540151060",oauth_consumer_key="gspbtp69ui7n",oauth_callback="http%3A%2F%2Fwww.ustartme.com%3A80%2Flinkedin%2Fconnect.php%3FlType%3Dinitiate%26lResponse%3D1",oauth_signature_method="HMAC-SHA1",oauth_signature="DFVoKYq%2BHSScTggWLhFnPQZzikI%3D"
            [string] => POST&https%3A%2F%2Fapi.linkedin.com%2Fuas%2Foauth%2FrequestToken&oauth_callback%3Dhttp%253A%252F%252Fwww.ustartme.com%253A80%252Flinkedin%252Fconnect.php%253FlType%253Dinitiate%2526lResponse%253D1%26oauth_consumer_key%3Dgspbtp69ui7n%26oauth_nonce%3D46e3489d3a270b4d045f9550dc55d967%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1540151060%26oauth_version%3D1.0
        )

    [error] => OAuth callback URL was not confirmed by the LinkedIn end-point
    [success] => 
)


LINKEDIN OBJ:

LinkedIn Object
(
    [callback:protected] => http://www.ustartme.com:80/linkedin/connect.php?lType=initiate&lResponse=1
    [token:protected] => 
    [application_key:protected] => gspbtp69ui7n
    [application_secret:protected] => CV3S5ke2Lvd8hAoA
    [response_format:protected] => xml
    [last_request_headers] => Array
        (
            [0] => Authorization: OAuth realm="http%3A%2F%2Fapi.linkedin.com",oauth_version="1.0",oauth_nonce="46e3489d3a270b4d045f9550dc55d967",oauth_timestamp="1540151060",oauth_consumer_key="gspbtp69ui7n",oauth_callback="http%3A%2F%2Fwww.ustartme.com%3A80%2Flinkedin%2Fconnect.php%3FlType%3Dinitiate%26lResponse%3D1",oauth_signature_method="HMAC-SHA1",oauth_signature="DFVoKYq%2BHSScTggWLhFnPQZzikI%3D"
            [1] => Content-Type: text/plain; charset=UTF-8
        )

    [last_request_url] => https://api.linkedin.com/uas/oauth/requestToken
)