530 Valid hostname is expected when setting up IIS 10 for multiple sites
When configured with two or more hostnames, the correct virtual host name and username must both be sent in the username by the ftp client. Separate the site name and user with the vertical line symbol: |
So, in your FTP Client use this for the username:
It appears that you're attempting to connect to the FTP site using a hostname which is not currently configured in any of the bindings to the FTP site within IIS.
I base this only on the error output from Filezilla which you have included, as you have censored the hostname (even in example form) from the output, so there isn't much more to go on.
You'll need to configure a binding on the FTP site which matches the hostname you are using to connect to the FTP site (whether that be from Filezilla or any other FTP client).
EDIT: From your updated post information, I notice that your bindings for the FTP site are indeed incorrectly configured - you have currently only got the FTP site bound to the localhost loopback address (127.0.0.1). You will need to bind it to a non-loopback address, which is externally routable. Depending on your environment, this is likely to either be your external IP address (if mapped directly to the server) or an internal IP address (if you have NAT configured). My guess based on the current information is that you must have another FTP site configured, which is intercepting these requests and showing you the invalid hostname error. Once you configure this FTP site correctly, all should function as intended.
Additionally, @Dre's answer is also crucial (so you should also upvote it) - if you have more than one FTP site bound to the same IP address, you will need to specify the hostname in the 'user' field of your FTP client in the format