The changed-tiles component is responsible for executing the changed tiles SQL logic and store the list of changed tiles in a text file using pgclimb.
The actual logic for detecting the changed tiles is in the import-sql component.
After you have imported OSM data into postgis you can run changed-tiles. If you run it on a fresh import you will get all tiles as changed tiles. You need to run import-osm-diff first to get real changed tiles.
changed-tiles will store the list of changed tiles in ./export/tiles.txt.
docker-compose run changed-tiles