When you click on the meet up link it takes you to the drop off link.
I did eventually find the departure point after scanning the full message but not until I had missed my bus. I contacted viator who basically said, can't help you, they refused to give a refund and were as much use as a chocolate fire guard (Cristine Joy). I would think again about using viator, I have had easier and better dealings with GETYOURGUIDE.
Thankfully after speaking to the bus company, who were excellent, I was able to transfer to a later bus. I then had an excellent shopping adventure with many bargains.