Power BI Customer Connector: Unsupported Grant Type Error (Vimeo API)

[rrredirect]

Hello,

I am attempting to create my first PowerBI Custom Connecter to connect to the Vimeo API. I am stuck on the final step of the authorization flow - getting back an access token. When trying out the Connecter in PowerBI, it seems to authenticate properly when I hit the access token endpoint, but I get back a warning "[unsupported_grant_type] Unsupported grant type" 

It appears I am not sending the grant_type properly in the request. Here are Vimeo's requirements of what is sent along in the body of the request:

Here is a snippet of code from the Customer Connector I am building. It is within this TokenMethod function that I am trying to fufill the requirements of the image above:

TokenMethod = (grantType, tokenField, code) =>
    let
        queryString = [
            grant_type = "authorization_code",
            redirect_uri = redirect_uri,
            client_id = client_id,
            client_secret = client_secret
        ],
        queryWithCode = Record.AddField(queryString, tokenField, code),

        authKey = "Basic " & Binary.ToText(Text.ToBinary("client_id:client_secret"),BinaryEncoding.Base64),

        tokenResponse = Web.Contents(token_uri, [
            Content = Text.ToBinary(Uri.BuildQueryString(queryWithCode)),
            Headers = [
                #"Authorization" = authKey,
                #"Content-type" = "application/json",
                #"Accept" = "application/vnd.vimeo.*+json;version=3.4"
            ],
            ManualStatusHandling = {400} 
        ]),
        body = Json.Document(tokenResponse),
        result = if (Record.HasFields(body, {"error", "error_description"})) then 
                    error Error.Record(body[error], body[error_description], body)
                 else
                    body
    in
        result;

I'm wondering if someone could please point out where I might be going astray in the code and why I am recieving the [unsupported_grant_type] error.

Many thanks for your time,

-Josh

[v-eqin-msft]

Hi  @rrredirect 

Sorry for that I'm not familiar with customer connector. But based on my researching,

1.The grant_type parameter must be set to “authorization_code”.

2.The grant_type , code, Client Authentication  paremeters are required.

So such error may be caused by the unknown "grantType"

TokenMethod = (grantType, tokenField, code) =>

Or no code parameter in 

 

Refer to:

Authorization code flow - Azure Active Directory B2C | Microsoft Docs

 Solved: OAuth 2.0 Authorization Code flow grant type - Pow... - Microsoft Power BI Community

Authorization Code Grant - OAuth 2.0 Simplified

In addition, you may post your issue on  Developer - Microsoft Power BI Community for further helps.

Best Regards,
Eyelyn Qin
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