I'm trying to connect to Stack Exchange API using OAuth. 
So far I've been able to get a token and retrieve data that does not require authentication.
When i try do query that uses the authentication, I'm getting error 400 - Bad request.
Here's the code:
        
    Dim Key As String = "(app_key)"

    Dim RequestURL As String = "https://api.stackexchange.com/2.2/me/questions?access_token=" & Token & "key=" & Key & "&order=desc&sort=activity&site=stackapps"
    
    Dim Handler As HttpClientHandler = New HttpClientHandler()
    If Handler.SupportsAutomaticDecompression Then 
           Handler.AutomaticDecompression = DecompressionMethods.GZip Or DecompressionMethods.Deflate
    End If

    Dim HttpClient As HttpClient = New HttpClient(Handler)

    Dim query = Await HttpClient.GetAsync(RequestURL)

    If query.IsSuccessStatusCode = True Then
         '(query.Content.ReadAsStringAsync())
    End If

Tried using only key, only access token, or none in the request, but received the same error. Also tried adding "OAuth" header and "access_token":
        
    HttpClient.DefaultRequestHeaders.Authorization = New AuthenticationHeaderValue("OAuth", Token)
    HttpClient.DefaultRequestHeaders.Authorization = New AuthenticationHeaderValue("access_token", Token)

Any help appreciated.