To initialize your local repository using the LineageOS trees, use a command like this:

repo init -u https://github.com/openfde/fde-manifests -b fde_14 --git-lfs

Then to sync up:

repo sync

compile

source build/envsetup.sh 

syncFdeApk 

download the latest boringdroidSystemUI apk from web by running command syncFdeApk

breakfast fde_x100_arm64 user

make -j4