Here is the Coloniae endpoint for stats collection :
Put this url inside the Statistics window of your world :
and you will soon get listed on Coloniae ! See the Worlds Index here
with all worlds using the service.
Note that it only works for server owners. If you play on someone else's server, ask them to add the endpoint. If you are playing on your own save, this means you have an "embedded server" so you can add it yourself.
As of 6 May 2022 this is still in the very early stages !