Non-static method requires a target. in .net core 3.1 application trying to call .net standard library

I am trying to call a static method of a static class via reflection but getting exception Non-static method requires a target

My class in .net standard 2.1 library is

    namespace MyNameSpace
    {
        public static class MyClass
        {            
            public static string DecryptData(string input)
            {                
                return ....;    
            }
        }
    }

My code for calling the class in .net core application is

    private string GetDetails(string data)
    {
        string content = null;            
        Type dllType = null;
        var asm = Assembly.LoadFrom(fileName);
        foreach (var t in asm.GetTypes())
        {
            if (t.IsClass && t.IsPublic)
            {
               dllType = t;
               break;
            }
        }
        
        if (dllType != null)// class successfully found
        {
            MethodInfo staticMethodInfo = dllType.GetMethod("DecryptData");//method successfully found                
            var o = staticMethodInfo.Invoke(null, new object[] { data });//exception on this line
        }
        return content;
    }