Thank you very much for your answer but still 404. Could you please write down exactly the address for this version (18.104.22.168a) and I will understand from now and on what to do. Thank you again for your patience!
In Linux-land, escaping means - usually, but not always - to prefix with a \ character (other characters may be used depending on the specifics of the system in question). It's used to indicate that a character that would otherwise have a special purpose should be treated as a literal character.
For example, "/" is the separator between directories and filenames. "\/" means the literal character "/" without any special purpose.
So, removing all the escape sequences - all the "\" characters - leaves "https://content-system.gog.com/open_link/download?path=/open/galaxy/client/22.214.171.124/setup_galaxy_126.96.36.199a.exe
" which is the URL for the installer.