How to migrate from Passport authentication type to OAuth 2.0

Hello,

Got this error while attempting to connect to Dynamics CRM 365 OrganizationService:

Error Message: 

System.ServiceModel.FaultException
HResult=0x80131501
Message=An error occurred when processing the security tokens in the message:You are using Ws-Trust authentication which has been deprecated and no longer supported in your environment. Please use OAuth2.0 authentication.
Source=mscorlib
StackTrace:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at Microsoft.Xrm.Sdk.IOrganizationService.Create(Entity entity)
at Microsoft.Xrm.Sdk.Client.OrganizationServiceProxy.CreateCore(Entity entity)
at Microsoft.Xrm.Sdk.Client.OrganizationServiceProxy.Create(Entity entity)
at Microsoft.Xrm.Client.Services.OrganizationService.<>c__DisplayClassd.b__c(IOrganizationService s)

Used this “Ws-Trust authentication which has been deprecated and no longer supported in your environment. Please use OAuth2.0 authentication” to search around and the answer was to change the connection string to something like this: 

connectionstring = “AuthType=OAuth;Username=jsmith@contoso.onmicrosoft.com; Password=passcode;Url=contosotest.crm.dynamics.com;AppId=51f81489-12ee-4a9e-aaae-a2591f45987d; RedirectUri=app://58145B91-0C36-4500-8554-080854F2AC97;LoginPrompt=Auto”

But I tried that (substituted with my own secrets) but it still gave me same error.      

Here are the codes to connect:

using Microsoft.Xrm.Client;

….

private readonly CrmConnection _crmServiceConnection;

in the constructor, set:

    _crmServiceConnection  = CrmConnection.Parse(dynamicsConfigurationProvider.ConnectionString);

And the connection is used in 

{
using (var service = new OrganizationService(_crmServiceConnection))
{
var accountId = service.Create(dynamicsAccount);

}
}

I looked up the OrganizationService meta data and it seemed old:

#region Assembly Microsoft.Xrm.Client, Version=7.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
// C:Users.userid.nugetpackagesmicrosoft.crmsdk.extensions7.1.0.1libnet45Microsoft.Xrm.Client.dll
// Decompiled with ICSharpCode.Decompiler 6.1.0.5902
#endregion

Thanks in advance for your help!!