There are many other corner cases, but here are some of the most common authentication responses from Solr.
If Authorization is configured in Solr, and a call is rejected by authorization, then a HTTP 403 response is returned
HTTP/2 401
content-security-policy: default-src 'none'; base-uri 'none'; connect-src 'self'; form-action 'self'; font-src 'self'; frame-ancestors 'none'; img-src 'self'; media-src 'self'; style-src 'self' 'unsafe-inline'; script-src 'self'; worker-src 'self';