I have money in cash - USD.
I need to put this on the account (in any of these countries: CZ, PL, DE).
In which bank such deposit is the cheapest or free?
There are many more knowledgeable than I on this site, and that can answer your question more comprehensively, but N26 is mentioned a lot on Nomad/Gate. The link is for their German website (in english). I wouldn’t be surprised if N26 had a presence in all three countries. N26 The Mobile Bank | Voted 'Best bank in the world 2021'