Box Sign App Not Showing up

Hi there, 

Welcome to Box Community! 

To utilize Box Sign please make sure you've enabled. And to check: 

To change which of your users have Box Sign enabled or disabled:

1. In the left sidebar of the Admin Console, click Enterprise Settings.
2. In the top bar, click Box Sign.
3. Click Edit Configuration from the Configure Sign section.
4. Select the enablement option.
   • If you enable or disable Sign for select users or groups, type the user names, email addresses or names of groups you want to allow or deny. 
5. Click Save.

Meanwhile, to find out more about your Box Sign configuration here. 

Hope it helps! Let us know if you have further queries.