To set user permission, you can follow the steps below :

1. Go to your Xendit dashboard
2. Click Settings
3. Click Your Team > Team Members
4. If a user is not yet added, click "Invite Member" and register the email along with the permissions
5. If a user already added, click the pencil logo next to the email
6. You will be directed to the user detail page.  Tick the permissions you want to give to the user.  
7. Click Save once you are done.   

For further information, you can read more here.