Install and configure Genesys Cloud for External Routing

Hello, I followed the steps from this article: Install and configure the Genesys Cloud for Salesforce External Routing package - Genesys Cloud Resource Center. ( a lot of broken links to help articles)

Enable Chat Setting is not available , do we need to set up Messaging for In-App and Web?

When installing the external routing package, i got the following errors :
"ExternalROutingController: Depedent class is invalid and needs recompilation: Class ExternalRoutingService: Invalid type: LiveChatTranscript"