Man pages matching name pmlookuplabels in section 3:

pmLookupLabels.3.en	debian 10 / libpcp3-dev
pmlookuplabels.3.en	debian 10 / libpcp3-dev
pmLookupLabels.3.en	debian 11 / libpcp3-dev
pmLookupLabels.3.en	debian 12 / libpcp3-dev