Thanks for your post.
First make sure you have watched the beginner's tutorial on how to use the wall tool, see video here: https://youtu.be/mlyUoJYpAPA
Second, make sure you have your material library synced as per the below steps:
1. Head to the Job tool
2. Scroll down to settings and click Set
3. Select United States
from the Material Library
4. Click Submit
Here is a video on how to sync your material library: https://youtu.be/1OZrgIwUzVs
The double check there are no red fields in the dialogs preventing your from clicking submit and drawing the wall.
Let me know how you go!