Man pages matching name curlopt_sslengine_default in section 3:

CURLOPT_SSLENGINE_DEFAULT.3.en	debian 10 / libcurl4-doc
CURLOPT_SSLENGINE_DEFAULT.3.en	debian 11 / libcurl4-doc
CURLOPT_SSLENGINE_DEFAULT.3.en	debian 12 / libcurl4-doc