Troubleshooting
The four things that account for nearly every support message about a fresh install.
The widget does not appear.
Check three things in order: that you are looking at the published site rather than an editor preview, since several platforms do not run custom code in preview; that the current domain is on the allow-list, including the www variant; and that the snippet landed before the closing body tag rather than somewhere the platform strips scripts.
It refuses things it should know.
Almost always a coverage problem rather than a tuning one. Open the source list and confirm the page that answers the question was actually crawled — pages linked from nowhere are never discovered. If it is missing, add it directly; if it is not written yet, the gap report will keep reminding you.
An answer is wrong but confident.
Read the citation. A wrong answer with a citation nearly always means the cited page is out of date — an old pricing or policy page that is still indexed. Stale content is worse than missing content, because it produces authoritative answers with a source attached.
The API returns 403.
API access is an Agency plan feature and is checked on every request rather than when the key is created. A key that worked yesterday and 403s today usually means the plan changed, not the key.