Web service json in c# header password and username

when ı test web service (json service) by SOAP UI ,ı got correct response but ı have not managed using c#.

could you tel me how can access this web service by c#

service query raw in SOAP UI like this GET https://ws.teias.gov.tr/apigateway/prod/yanhizmetler/YanHizmetlerServiceRest/getBaraDegerleri?gecerlilikTrh=2018-02-20 HTTP/1.1 Accept-Encoding: gzip,deflate password: XXXXX username: 40X000000005030W Host: ws.teias.gov.tr Connection: Keep-Alive User-Agent: Apache-HttpClient/4.1.1 (java 1.5)