Cannot Print Label With Charactor - In S’abonner

Please assist.

Before I print my label i get prompt to enter some data like what the items code is that I want to use. The prompt box doesn't have any restrictions but as soon as I enter the - sign I cannot type anything else.

Can you please tell me what the solutions is to this as I cannot not go. Any futher with my project.

Thanks in advance
Janlo