Hello!
My name is Nikolay, I draw OpenStreeMap.
you made an excellent service, but violate the rules of using Openstreetmap
I noticed that you are using tiles with OSM data from mapy.cz.
According to the terms of use of OSM, you must specify a reference to the data source
We demand that you use the credit "© OpenStreetMap contributors".
For a browsable electronic map, the credit should appear in the corner of the map.
see more here
https://www.openstreetmap.org/copyright/en
I hope you stop violating the terms of use of openstreetmap
Nikolay Petrov,
openstreetmap contributor