In order to add users to your Business+ account you need to follow the next steps.
Step 1 – Open the FileDrop add-on and wait for it to load.
Step 2 – Click on the “Premium subscription” button to open the payments panel.
Step 3 – Update the number of users you want to add and make the payment. Once the payment is done come back to this panel.
Step 4 – Add the email addresses of your users in the users field.
Users can be removed from the same panel.