public delegate void TestDelegate();

public static class ExampleOne
{
    public static Action<string, bool> OnFunctionCall
        => (message, flag) => Console.WriteLine("Example");
}

public static class ExampleTwo
{
    public static TType CreateDelegate<TType>(Action<string, bool> onFunctionCall)
        where TType : class
    {
        var method = new DynamicMethod($"{Guid.NewGuid()}", typeof(void), Type.EmptyTypes, typeof(TType), true);

        ILGenerator il = method.GetILGenerator();

        // loading the first string argument
        il.Emit(OpCodes.Ldstr, method.Name);

        // not sure here how to load boolean value to the stack
        il.Emit(OpCodes.Ldc_I4_0);

        // this line doesn't work
        // example two has no idea about ExampleOne
        // is it possible to load the reference of the Action<string, bool> to the stack and call it ?
        il.Emit(OpCodes.Call, onFunctionCall.Method);

        il.Emit(OpCodes.Ret);

        return method.CreateDelegate(typeof(TestDelegate)) as TType;
    }
}

public class Program
{
    public static void Main(string[] args)
        => ExampleTwo
            .CreateDelegate<TestDelegate>(ExampleOne.OnFunctionCall)
            .Invoke();
}