Request token retrieval failed:

RESPONSE:

Array
(
    [linkedin] => Array
        (
            [oauth_problem] => timestamp_refused
            [oauth_acceptable_timestamps] => 1575666410+-900
        )

    [info] => Array
        (
            [url] => https://api.linkedin.com/uas/oauth/requestToken
            [content_type] => application/x-www-form-urlencoded;charset=UTF-8
            [http_code] => 400
            [header_size] => 744
            [request_size] => 516
            [filetime] => -1
            [ssl_verify_result] => 0
            [redirect_count] => 0
            [total_time] => 0.199838
            [namelookup_time] => 0.027868
            [connect_time] => 0.028659
            [pretransfer_time] => 0.052982
            [size_upload] => 0
            [size_download] => 77
            [speed_download] => 385
            [speed_upload] => 0
            [download_content_length] => 77
            [upload_content_length] => -1
            [starttransfer_time] => 0.199811
            [redirect_time] => 0
            [redirect_url] => 
            [primary_ip] => 185.63.145.4
            [certinfo] => Array
                (
                )

            [primary_port] => 443
            [local_ip] => 172.16.36.101
            [local_port] => 41303
        )

    [oauth] => Array
        (
            [header] => Authorization: OAuth realm="http%3A%2F%2Fapi.linkedin.com",oauth_version="1.0",oauth_nonce="d934646857a6d934d9a6df5a326886a8",oauth_timestamp="1575665469",oauth_consumer_key="75agoppj0tdoix",oauth_callback="http%3A%2F%2Fkarriere.findingheads.de%3A80%2Fxing%2Flinkedin-1.php%3FlType%3Dinitiate%26lResponse%3D1",oauth_signature_method="HMAC-SHA1",oauth_signature="VjBBNH3x2m3N%2Ftmnxb78mrasFyU%3D"
            [string] => POST&https%3A%2F%2Fapi.linkedin.com%2Fuas%2Foauth%2FrequestToken&oauth_callback%3Dhttp%253A%252F%252Fkarriere.findingheads.de%253A80%252Fxing%252Flinkedin-1.php%253FlType%253Dinitiate%2526lResponse%253D1%26oauth_consumer_key%3D75agoppj0tdoix%26oauth_nonce%3Dd934646857a6d934d9a6df5a326886a8%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1575665469%26oauth_version%3D1.0
        )

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


LINKEDIN OBJ:

LinkedIn Object
(
    [callback:protected] => http://karriere.findingheads.de:80/xing/linkedin-1.php?lType=initiate&lResponse=1
    [token:protected] => 
    [application_key:protected] => 75agoppj0tdoix
    [application_secret:protected] => gKmyvVBQwCAUdpKI
    [response_format:protected] => xml
    [last_request_headers] => Array
        (
            [0] => Authorization: OAuth realm="http%3A%2F%2Fapi.linkedin.com",oauth_version="1.0",oauth_nonce="d934646857a6d934d9a6df5a326886a8",oauth_timestamp="1575665469",oauth_consumer_key="75agoppj0tdoix",oauth_callback="http%3A%2F%2Fkarriere.findingheads.de%3A80%2Fxing%2Flinkedin-1.php%3FlType%3Dinitiate%26lResponse%3D1",oauth_signature_method="HMAC-SHA1",oauth_signature="VjBBNH3x2m3N%2Ftmnxb78mrasFyU%3D"
            [1] => Content-Type: text/plain; charset=UTF-8
        )

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