I have an Azure app that returns a bearer access token. I use the Windows Account Manager (WAM) so there’s a special redirect URI. I’m using the following code to refresh the token but I’m getting a 400 response. I am sending the access code before it expires and I get the redirect URI right off Azure. I’m not certain though on the url of the PostAsync:

public async Task<string> RefreshTokenAsync(string refreshToken, string Tenant, string Instance, string ClientId)
        {

            using (var client = new HttpClient())
            {
                var content = new FormUrlEncodedContent(new[]
                {
                    new KeyValuePair<string, string>("grant_type", "refresh_token"),
                    new KeyValuePair<string, string>("client_id", ClientId),
                    new KeyValuePair<string, string>("refresh_token", refreshToken),
                    new KeyValuePair<string, string>("redirect_uri", "ms-appx-web://microsoft.aad.brokerplugin/" + ClientId)

                });

                var response = await client.PostAsync($"{Instance}{Tenant}/oauth2/v2.0/token", content);

                if (response.IsSuccessStatusCode)
                {
                    var responseJson = await response.Content.ReadAsStringAsync();
                    var responseObject = JsonConvert.DeserializeObject<TokenResponse>(responseJson);
                    return responseObject.AccessToken;
                }
                else
                {
                    string a = await response.Content.ReadAsStringAsync();
                    MessageBox.Show(a , "Error", MessageBoxButton.OK);
                    return string.Empty;
                }
            }

        }

        public class TokenResponse
        {
            [JsonProperty("access_token")]
            public string AccessToken { get; set; }
        }

Is there a simpler way to refresh a token?