SalesIQ Online Visitor not displayed in CRM

SalesIQ Online Visitor not displayed in CRM

Hello,

I have 2 users who are
- administrator in CRM
- administrator in SalesIQ

The SalesIQ - CRM integration is active.

For one users, the Visitor Online "widget" (I don't know how it is called") is displayed at the bottom of her CRM window (screenshot)

For the other user, the Visitor Online "widget" is not available. What am I missing something in the configuration so the second user has the widget?