fcitx5-flypy provides flypy table for fcitx5.
You need to install fcitx5-table fcitx5-lua and libime first.
sudo apt install build-essential cmake-extras extra-cmake-modules \
gettext appstream libecm-dev \
ibfcitx5core-dev libboost-dev libimecore-dev libimetable-dev
make build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=/usr
make -j4
sudo make install