In order to have the PCI button available in SCV admins must create a new voice extension. A short video on how to do this can be found here.
The code needed to create the Aura component is
<aura:component implements="opencti:availableForVoiceExtension,flexipage:availableForAllPageTypes,flexipage:availableForRecordHome" access="global"> <nbavs:pciAgentAssist/> </aura:component>