Man pages matching name pqparamsendqueryprepared in section 3:

PQparamSendQueryPrepared.3.en	debian 10 / libpqtypes-dev
PQparamSendQueryPrepared.3.en	debian 11 / libpqtypes-dev
PQparamSendQueryPrepared.3.en	debian 12 / libpqtypes-dev