Welcome, Marjan.
I've added a link to your post that is the closest I could find to a manufacturer's site. Not sure it is, but if it's close enough to what you want we'll leave it.
In the ceramic tile industry in this country that would qualify as a Specialty Tile. As such, there are really no requirements, but the manufacturer can have the tile tested under various portions of the ANSI A137.1 protocol for ceramic tile and have his tile certified as having passed those portions of the certification for ceramic tile. I don't know how common it is for a foreign maker of that sort of Specialty Tile to have such testing done, but I think it would be rather rare. That said, all you can reasonably expect to be certain of is that whatever you find in the box is what you bought. If the manufacturer references any parts of A137.1, you would at least know the tile meets those portions, but not the entire certification.
I saw nothing at all on the site I linked that speaks to the installation or maintenance of those tiles. And given that they are a Specialty Tile, the installation would need to be specified by the manufacturer. Absent such installation instructions, you're mostly on your own.
Do you really need a professional tile setter experienced with that particular tile? Well, it always helps to have experience, but a good pro could likely figure it out. Best way to determine whether you need a pro at all would be for you to make up a test board or two or three and see what you think of the result. If it appears you can DIY, that's what I would recommend for an installation most closely matching your expectations.
Without knowing your intended application (like what part of your bathroom) the only general advice I would hazard is to use at least a minimal (1/16th") grout joint. Rarely ever a good idea to butt-join any sort of ceramic tile.
My opinion; worth price charged.