FTP URLs
How to turn on in safari
iPhone XS Max, iOS 15
Question marked as
You can make an attempt enabling FTP support enabled in the Develop -> Experimental Features menu.
Develop menu is enabled in Safari's Preferences... -> Advanced -> Show Develop menu in menu bar
I don't think it will work, though. You better connect to an FTP server using a dedicated client (Cyberduck, Forklift, etc).