Hi on this page
https://getbootstrap.com/docs/4.0/components/forms/
we get :
Failed to load resource: the server responded with a status of 404 (HTTP/2.0 404)
[Error] Failed to load resource: the server responded with a status of 404 (HTTP/2.0 404) (docsearch.min.js.map, line 0)

https://cdn.jsdelivr.net/docsearch.js/2/dist/cdn/docsearch.min.js.map