As others have mentioned, the entire 2016+ MBP generation (and I think the 2014/2015 as well), the batteries are glued to the topcase, so when you get a new battery, you get a whole new topcase which includes keyboard, trackpad, speakers. So it's actually a really good "value" if your battery needs servicing, as you get a whole bunch of other stuff for free.
Given that however, Apple won't replace the battery unless it's showing <80% battery health (eg. you can't just ask to get it replaced even if you're willing to pay the fee).
@Sanpete, not sure what you're referring to here. I don't think there was a battery replacement program for the 2018 15" MBP's? You might be referring to the Butterfly Keyboard Service Program, which would replace the keyboard (which includes the topcase and thus a new battery) if your keyboard was having issues (Eg. double-key strokes, missing key strokes, etc.)
OP, where are you located? Do you have access to an Apple Store? If you do, highly recommend you take it directly to an Apple Store, who does it for $199 (not sure what the Euro-price is, I think it's E199), all-in. If you don't, then I guess this is the only option unless you qualify for one of the existing service programs.