Please activate SightCall for Salesforce through the Services Portal.
First connect to your Sightcall admin and click on "Services" :
Then click on the "+" button under "Integration" in the Home page :
Finally, click on the integration that you would like to activate and fill the form :
Register your SightCall package
To register your SightCall for Salesforce package, please enter the SightCall API Key and your Salesforce domain. For each of those fields, click on How to for further explanations.