TeamViewer QuickJoin not working

Hi, I got 10 users, and as an administrator, I just assign 1 email address to 10 of them to use for login the TeamViewer. I want 10 of them to use the same email address during they login time or consult with the customer. I also create own customised quick support module under that email address. Now the problem is 10 of them could not do the remote session with the customer. They not able to connect with customers. I suspect something wrong in TeamViewer configuration. Please advise us how to manage 10 users that using 1 email address to log in the TeamViewer