Embedded Service Chat Widget Offline in Digital Experiences Due to Content Security Policy (CSP) Error

When accessing a Digital Experiences (Community) site, the Embedded Service Chat widget may not go online even when agents are available and in an online status. This occurs due to a Content Security Policy (CSP) configuration issue in the Community Builder.
A Content Security Policy (CSP) is a browser security feature that restricts which external resources a web page can load. When the CSP setting in Community Builder does not include the required Salesforce Live Agent endpoint with a trailing slash, the embedded chat widget fails to initialize.
The following error appears when viewing the community via the Builder option in Setup:
"Access to [Live Agent endpoint URL] for script resources violates your Content Security Policy (CSP). To get access to those script resources, change your Security Level on the Security page in your community's settings."
The exact URL in the error varies depending on the org's Live Agent endpoint and identifying information specific to the org.