How to use .NET DLL in AX

Please refer the below blog com

You can create .net class library project.
Register the .dll into dynamic AX

Code:

static void PushNotification(Args _args)
{
   
   CodeAccessPermission permission;
   PushNotificationAPI.PushNotification push;
 ;
   

 permission = new InteropPermission(InteropKind::CLRInterop);
 permission.assert();
 push = new PushNotificationAPI.PushNotification();
 push.SendAndroidPushNotification("Great Ashraf", "dZzhpCacCMQ:APA91bEMAMorxr9hCGoSx5WCrR1eocjxPY30IDn9V0aWblp1lr6Bb2XQkS0glflLZt5x0LMXKKTbqydLoXxKgpBSYGy9SigEZBqyASxuRGSUBARTvFfx-WUmliBPV1cMAkDxSyJ4kTBM");
   
}
https://nasheet.wordpress.com/2012/05/21/how-can-we-use-dll-in-ax/