German "curl -X POST..." in b4a umsetzen

curl -X POST --header 'Content-Type: application/json' --header 'Accept: application/json' -d '{"username":"master","nonce":"masterpasswort"}' 'http://192.168.178.97/api/v1/auth/start'

    job1.Initialize("GetMyToken", Me)
    job1.PostString("http://192.168.178.97/api/v1/auth/start", "username=master&nonce=masterpasswort")
    job1.GetRequest.SetHeader("Content-Type:", "application/json")
    job1.GetRequest.SetHeader("Accept:", "Application/json")
    Wait For (job1) JobDone(job1 As HttpJob)
    If job1.Success = True  Then
        Log(job1.GetString)
    Else
        Log(job1.ErrorMessage)
    End If
    job1.Release

ResponseError. Reason: BAD REQUEST, Response: {"errors":{"":"None is not of type 'object'"},"message":"Input payload validation failed"}
{"errors":{"":"None is not of type 'object'"},"message":"Input payload validation failed"}

    Dim json1 As JSONGenerator
    Dim map1 As Map = CreateMap("username":"user", "nonce":"passwort")
    json1.Initialize(map1)
    
    Dim job1 As HttpJob
    job1.Initialize("GetMyToken", Me)
    job1.PostString("http://192.168.178.97/api/v1/auth/start", json1.ToString)
    job1.GetRequest.SetHeader("Content-Type:", "application/json")
    job1.GetRequest.SetHeader("Accept:", "application/json")
    Wait For (job1) JobDone(job1 As HttpJob)
    If job1.Success = True  Then
        Log(job1.GetString)
    Else
        Log(job1.ErrorMessage)
    End If
    job1.Release

    Dim json1 As JSONGenerator
    Dim map1 As Map = CreateMap("username":"user", "nonce":"passwort")
    json1.Initialize(map1)
    Dim job1 As HttpJob
    job1.Initialize("", Me)
    job1.PostString("http://192.168.178.97/api/v1/auth/start", json1.ToString)
    job1.GetRequest.SetContentType("application/json")
    job1.GetRequest.SetHeader("Accept", "application/json")
    Wait For (job1) JobDone(job1 As HttpJob)
    If job1.Success = True  Then
        Log(job1.GetString)
        job1.Release
    Else
        Log(job1.ErrorMessage)
        job1.Release
    End If