Trying to connect with api.postcode.nl using Basic Authorization does not work. I keep getting this result:

"exception":"Authorization not found.","exceptionId":"PostcodeNl_Controller_Plugin_HttpBasicAuthentication_NoAuthorizationHeaderFoundException"

I use "HttpGet" with extra headers.     

  01  EXTRA-HEADERS.
          05 filler                                              PIC X(13) value 'Authorization'.
          05 filler                                              PIC X value x"00".
          05 filler                                              PIC X(05) value 'Basic'.
          05 filler                                              PIC X value x"00".      
          05 LNK-USERNAME                    PIC X(100).
          05 filler                                             PIC X value x"00".         
          05 LNK-PASSWORD                   PIC X(100).
          05 FILLER                                        PIC X VALUE X"00".
          05 FILLER                                        PIC X VALUE X"00".          

I tried all kinds of values in de header but I keep getting no result.

In Postman it works fine so my username and password are correct.