Whenever I try to add associate a user with an organization, it returns “User doesn’t exist”, even though it exists (in the database) and with get.

private async Task<bool> AddUserToOrganization(string organizationId, string userId)
{
string adminToken = await GetAdminTokenAsync();
if (string.IsNullOrEmpty(adminToken))
{
    throw new Exception("Failed to fetch admin token.");
}

// Set the authorization header
_httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", adminToken);


var orgUrl = $"{_configuration["Keycloak:BaseUrl"]}/admin/realms/{_configuration["Keycloak:Realm"]}/organizations/{organizationId}/members";

var requestBody = new { userId = userId }; // Create the HTTP request
                                           
var request = new HttpRequestMessage(HttpMethod.Post, orgUrl) { Content = new StringContent(JsonConvert.SerializeObject(requestBody), Encoding.UTF8, "application/json") }; // Send the request
var orgResponse = await _httpClient.SendAsync(request);

if (!orgResponse.IsSuccessStatusCode)
{
    var errorResponse = await orgResponse.Content.ReadAsStringAsync();

    // Step 3: Perform cleanup
    await CleanupFailedOperationAsync(organizationId, userId);

    throw new Exception($"Failed to add user to organization. Status: {orgResponse.StatusCode}, Response: {errorResponse}");
}

return true;
}

I’ve tried changing the request body to:

{
   string[] requestBody= new[] { userId};
   string requestBody= userId;
   var requestBody = new {userId=userId};
   List<string> requestBody = new {userId};
}

I’m using keycloak v.26.0.7 with postgresql with docker. Any help would be greatly appreciated.