FileZilla
FileZilla is what I use to transfer files from my computer onto a Web server. FileZilla allows you to transfer files to your Web directories using FTP (File Transfer Protocol). So if you need FTP, then you need a program like FileZilla. Alternative programs for FTP are WS_FTP, WinSCP and Cyberduck.
FileZilla does not have dark mode, but I find that to be the only major flaw.