Unable to generate token for One-Drive using c# .net 6 - azure

Question

I am facing issue while trying to generated token for One-Drive access. As I have requirement where user can get all the files from there One Drive using my application.
I tried below code but I am getting error.
{"error":"invalid_grant","error_description":"AADSTS65001: The user or administrator has not consented to use the application with ID. Send an interactive authorization request for this user and resource.\r\nTrace ID: 33a0dd6a-6984-4c0a-8f74-6fbcd9c54301\r\nCorrelation ID: 265ca054-ab98-450c-8281-851ef6b0fdc3\r\nTimestamp: 2022-11-24 15:56:04Z","error_codes":[65001],"timestamp":"2022-11-24 15:56:04Z","trace_id":"33a0dd6a-6984-4c0a-8f74-6fbcd9c54301","correlation_id":"265ca054-ab98-450c-8281-851ef6b0fdc3","suberror":"consent_required"}
Find my code that I am trying.
public async Task GetTokenAsync(string tenant, string clientId, string
clientSecret, string username, string password)
{
HttpResponseMessage resp;
string token;
using (var httpClient = new HttpClient())
{
httpClient.DefaultRequestHeaders.Accept.Add(
new ("application/x-www-form-
urlencoded"));
var req = new HttpRequestMessage(HttpMethod.Post, $"https://login.microsoftonline.com/{tenant}/oauth2/token/");
req.Content = new FormUrlEncodedContent(new Dictionary<string, string>
{
{"grant_type", "password"},
{"client_id", clientId},
{"client_secret", clientSecret},
{"resource", "https://graph.microsoft.com/"},
{"username", username},
{"password", password}
});
resp = await httpClient.SendAsync(req);
string content = await resp.Content.ReadAsStringAsync();
var jsonObj = System.Text.Json.JsonSerializer.Deserialize<dynamic>(content);
token = jsonObj["access_token"];
}
return token;
}
Nothing

Answer 1

I tried to reproduce the same in my environment and got the same error as below:
The error usually occurs if you have not consented Admin Consent to the API Permissions you have granted like below:
To resolve the error, I created the Azure AD Application and granted Admin consent to the API Permissions:
To generate the access token, I used to the below parameters:
GET https://login.microsoftonline.com/TenantId/oauth2/token
grant_type:password
client_id:53f9d6e0-f9e8-4620-9e45-XXXXX
client_secret:Msd8Q~q~-2gb4sooQVGDIQQAI92gXXXXX
resource:https://graph.microsoft.com/
username:username
password:Password
I am able to generate the access token successfully as below:
If still the issue persists, try updating the below settings in Azure Enterprise Application like below:
Go to Azure Active Directory -> Enterprise applications -> User settings -> Consent and permissions
Otherwise, you can Grant admin consent by using below Endpoint, Login as Admin and Accept:
https://login.microsoftonline.com/TenantId/adminconsent?client_id=ClientID