Just a heads up: You may have seen my most recent comment on this branch. As it does not feasible to pursue a React-based Pi-hole v6.0 dashboard, I added PHP support into FTL's embedded web server.
You can already host the existing web interface as simple as
pihole checkout ftl new/http
and accessing the web interface at http://pi.hole:8080/admin. You may need to set the php-cgi path, however, the standard path should be fine for most setups. Note that, due to substantial changes to the API, many parts do not work at this time, however, there will be work going into this piece by piece.
This means that the branch is now officially revived and will lead the path into Pi-hole v6.0 (this is still a longer-term goal, ETA currently not before end of the year and maybe even afterwards).