You'll need the following dependencies:
libgranite-7-dev >= 7.7.0
libglib2.0-dev
libgtk-4-dev
libnotify-dev
libpulse-dev
libwingpanel-9-dev
meson (>= 0.57.0)
valac (>= 0.26)
Run meson to configure the build environment and then ninja to build
meson build --prefix=/usr
cd build
ninja
To install, use ninja install
sudo ninja install