Why cant i use playit.gg to connect to my ftp server?

i cant use playit.gg with ftp. i use filezilla server with xampp to host it and i can use it locally just fine. i also have a website and a minecraft server that work fine with playit.gg. but for whatever reson i cant use the windows file explorer to access but i can with my local ip on the local network: any ideas?

It is straight and simple. Go see the “What we provide” section of the home page; it says “TCP and UDP tunneling” with bold text. It does not say FTP. TCP, UDP. FTP, all three are distinct network protocols.