Hi, everyone! I downloaded this add-on, and I was having the same problems as you! I couldn't input dimensions into the text box. At a certain point, I gave up on using the add-on, but then suddenly I went to try it again it was working! Now, I don't know what I did to make it work, but I can list down everything significant that took place between the add-on not working and it suddenly working. At one point I reset my laptop. At another point I refreshed the page. While I was working, I had the idea to change the permission on the doc to -can edit, to see if that would work. Soon after, I tried it and it worked. But then I returned the permissions to -view only, and it still worked, so I'm not sure if that's a viable solution. I hope I helped at all, I'm just super happy it started working. It's perfect!