Chat User License is needed for agents to accept and assist the customers via Salesforce Chat feature. So, kindly check whether enough Chat User licenses are available in Salesforce Company Information Setup.
Digital Engagement SKU is needed for Digital Engagement Messaging.
Using Digital Engagement SKU Licenses, reach customers across every digital channel including mobile messaging, web chat, social networks, and more to provide a seamless service experience for service.
Please check this – https://www.salesforce.com/ca/editions-pricing/service-cloud/digital-engagement/
Available to Sales and Service cloud orgs(please check above link for more details).
In the above link, use “DOWNLOAD THE FULL EDITION COMPARISON CHART” and check the “Digital Engagement SKU Includes” section.
Trailhead Resources:
https://trailhead.salesforce.com/en/content/learn/modules/service_digital_engagement
