As you can see in the documentation and inspector it is stated that "Presets for all providers and map types are provided for testing purposes".
This is done so that you can compare and choose the right provider for your application.

Here is an example of how to use Tiles API:
https://infinity-code.com/atlas/online- … esAPI.html

I always recommend using legal ways as much as possible.
But whether to follow my recommendation or not is your choice.

I have a question about the licensing. You mention in your manual that the "legal way" would be to use Google Map Tiles API.
Why does it work already now without having an API key for Map Tiles?
And how would I force the plugin to use our (not yet) purchased Map Tiles API if it works without it, too?
We're thinking about the costs we would have to calculate with.

What would be the way to go here, where does Online Maps get the tiles from?

Thanks in advance!