Man pages matching name qwtdyngridlayout in section 3:

QwtDynGridLayout.3.en	debian 10 / libqwt-doc
QwtDynGridLayout.3.en	debian 10 / libqwt5-doc
QwtDynGridLayout.3.en	debian 11 / libqwt-doc
QwtDynGridLayout.3.en	debian 12 / libqwt-doc