The checkbox will be there if you install gnome-control-center-x11-scaling as this is a Ubuntu feature, but I would suggest to also install mutter-x11-scaling , so you can use it on both, Wayland and Xorg.
Or if you don’t want to install the packages, on Wayland run: gsettings set org.gnome.mutter experimental-features "['scale-monitor-framebuffer']"