Custom connector API - TOKEN (error binary)

[Doc-tan]

I have create a custom connector but i can not see and use the token because of error

Details: "We cannot convert a value of type Binary to type Text."

at the postman i can post the same url with the same header and body and answer me with json 

{

    "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJiZX",

    "refresh": "Srbwtr7J"

}

my code:

let

                        creds = Extension.CurrentCredential(),

                        Response =

                            Web.Contents(

                                    server &"SignIn",

                                    [

                                        Headers = [

                                                    #"Content-Type" = "application/json",

                                                    #"api-version" = "1.0"

                                                    ],

                                        Content =

                                                    Text.ToBinary(

                                                                    Json.FromValue([

                                                                    username = creds[Username],

                                                                    password = creds[Password],

                                                                    afm = "",

                                                                    code = ""

                                                                    ])

                                                                )

                                    ]

                                        ),

                        JsonResponse = Json.Document(Response),

                        Token =  JsonResponse[token]

[v-hjannapu]

Hi @Doc-tan,
Thank you  for reaching out to the Microsoft fabric community forum.

The problem is happening inside the Power Query custom connector. In Power Query, the response coming from Web.Contents is treated as Binary by default. But later in the code, it’s being read like normal text/JSON. Because of this mismatch, Power Query throws the error saying it can’t convert Binary to Text, and the token is not getting read.

So this is not related to headers, body, or login details. It’s only a response handling issue in the connector. Once the response is properly handled as JSON, you should be able to access the token without any problem.

please go through with the below document hope it may resolve your Issue:
Json.Document - PowerQuery M | Microsoft Learn
Web.Contents - PowerQuery M | Microsoft Learn
Hope the above provided information help you resolve the issue, if you have any further concerns or queries, please feel free to reach out to us.
Regards,
Community Support Team.