Authenticate to SharePoint online inside our console application if we have SharePoint app-only permissions disabled

Question

On old created Office 365 tenants I use to authenticate to SharePoint online inside our C# console application using this code:

static void Main(string[] args)
{
               
    string siteUrl = "https://***.sharepoint.com/sites/CustomerServiceKB/";
    string clientId = "******";
    string clientSecret = "*****";
    using (ClientContext context = new OfficeDevPnP.Core.AuthenticationManager().GetAppOnlyAuthenticatedContext(siteUrl, clientId, clientSecret))
    {
       ...
    }
}

But, as per my knowledge newly created Office 365 tenants has SharePoint app-only permissions disabled.

So will my above code fail to work if the SharePoint app-only permissions is disabled inside our newly created tenant?

Edit

now based on the reply i got from @Asad >> he linked me to this blog >> https://sharepointstew.wordpress.com/2021/07/07/app-only-authentication-in-sharepoint-online-using-latest-azure-sdk/ >> but this blog is using PnP.Framework.AuthenticationManager which is based on this link @ https://www.nuget.org/packages/SharePointPnPCoreOnline is deprecated as well... so how i can authenticate my .net core console application to SharePoint using non-deprecated approach? i feel that i will never get an answer ..

Answer 1

I would advice you to check DisableCustomAppAuthentication property on your tenant. If it's set to True then your code will throw Unauthorised error.

Use below commands to enable authentication using client ID and client Secret.

Set-SPOTenant -DisableCustomAppAuthentication $false

Or alternatively, you can run this PnP commandlet:

Set-PnPTenant -DisableCustomAppAuthentication $false

Refer blog for more details: https://www.koskila.net/literally-breaking-changes-to-app-authentication-on-sharepoint-%F0%9F%98%B5/