Early in the design phase, the marker is mightier than the keyboard. Unfortunately yours seems to be empty. Fortunately you can refill the marker easily, all you need is a new container of ink. Order a refill from the providers listed below (not affiliate links, just quick access).
Obviously I'm curious what you used your first batch of ink on. What models did you come up with? Let me know, I'm interested to learn how you overcame the challenges you faced, big and small.