How to connect any tenant SharePoint without credentials

[KaushalKhamar]

Hello

I want to create 1 product for sharepoint online assessment which is Web bases and having the Windows authentication

1. This product is web based which is MVC core website in which any user from any tenant can login with their Microsoft account and user will give some input and submit the assessment
2. On submitting Azure function will be called which is Powershell Azure function.

So how can i connect SharePoint without credential of any tenant from the web application?

I had tried it using Windows authentication and from that i get the access token but that access token does not work in Azure function for getting the sharepoint connection in azure function

I had used below code to get the access token in web site
string userObjectID = (User.FindFirst("http://schemas.microsoft.com/identity/claims/objectidentifier"))?.Value;

AuthenticationContext authContext = new AuthenticationContext("https://login.windows.net/1a86a77c-9af1-47b4-980b-03ef62f12e63/oauth2/authorize", new NaiveSessionCache(userObjectID, HttpContext.Session));
ClientCredential credential = new ClientCredential(AzureAdOptions.Settings.ClientId, AzureAdOptions.Settings.ClientSecret);
result = await authContext.AcquireTokenSilentAsync("https://graph.microsoft.com", credential, new UserIdentifier(userObjectID, UserIdentifierType.UniqueId));

//Calling Azure Function
HttpClient _client = new HttpClient();
HttpRequestMessage newRequest = new HttpRequestMessage(HttpMethod.Get, "https://onlineassessment.azurewebsites.net/api/HttpTriggerPowerShell1?code=4gmK34HVbXdAkoa5jgo9kSA1y6OaIy1kTWg1gQhCeSa/Ka1G7vKFsg==&name=" + result.AccessToken);
HttpResponseMessage response1 = await _client.SendAsync(newRequest);