Client-side search is supported natively by a Javascript library. Search results are tuned to leverage the structure of your PreTeXt project. As such, as of 2022-10-27, development and support will favor this approach over our legacy support for an online service (Section 29.9).
Employing a switch in the publication file will provide search boxes (top banner, lower-right corner) and all the supporting infrastructure. See Subsection 44.4.10 for details.