Can't connect to FTP

Can you double check your credentials, the error looks like the problem with authentication?

Double check your FTP server configuration and the firewall dealing with PASV mode.  You should configure the FTP server a smaller scope of ports.
The error as pesos pointed out is with the configuration, but not with credentials but your client configuration requiring secure (TLS) connection.

If you decide you want FTP over TLS, make sure to setup the certificate/TLS portion of proftpd.

Double check your FTP server configuration and the firewall dealing with PASV mode.  You should configure the FTP server a smaller scope of ports.
The error as pesos pointed out is with the configuration, but not with credentials but your client configuration requiring secure (TLS) connection.

If you decide you want FTP over TLS, make sure to setup the certificate/TLS portion of proftpd.

Did you try connecting to the FTP by any chance? What error did you get?

Also it's not a firewall issue afaik, I've connected to another FTP server (Hostupon.com shared server) using the same software (WinSCP/FileZilla).

Look at your errors. Your client kept sending AUTH TLS to which the server reply NO (500). Your client tries again, AUTH TLS, the server response NO (500)
Your client then gives up and tries to send the username to which the Server response is NO ... (500).
It looks as the client defaults to trying to secure the connection.

Once you remove the above, Peos pointed out that you should check your credentials.
You posted one but in the error you have a completely different set of credentials.

I got 530 Login authentication failed.
It looks like wrong user name or password

You posted one but in the error you have a completely different set of credentials.

The host/username/password are all correct.
I know they're correct because I use the same login to connect to the hosting website.

Once you remove the above, Peos pointed out that you should check your credentials.

"It looks like wrong user name or password"
Just to verify,

Username = php-lessonS <- not php-lesson
Pass = temporarytestftp

You get authentication failure, keep saying that the information is correct makes little sense. If you use Cpanel to then access the FTP site access from an authorized system might be allowed but from anywhere else it will be rejected.

I am puzzled why you insist on trying to publish what most would consider as unwise disclosure of credentials that could expose your host unnecessarily.

If those credentials are correct, you have to use them in the way authorized.  Check your Cpanel, etc and authorize your wan ip as authorized to use this login credentials to access this site.

rgb192 - where are you located? That site is not reachable for me (UTC + 01:00).

I use both passive and not passive mode and still 530 authentication failed.
It looks like wrong password for FTP or php-lessons user is not allow to use FTP

>> I know they're correct because I use the same login to connect to the hosting website.
No, they do not need to be the same. Logging on to the hosting site (webpage) does not mean that passwords are the same for uploading  (ftp). The password you've specified is not correct for an FTP connection. Several people have tried (including myself), the password is not correct.

ftp php-lessons@145.14.144.10
Connected to 145.14.144.10.
220 ProFTPD Server (000webhost.com) [::ffff:145.14.144.10]
331 User php-lessons OK. Password required
Password:
530 Login authentication failed
ftp: Login failed
ftp>

Logging on to this hosting website requires an email address + password - not a username + password. So credentials are not the same.

"Logging on to this hosting website requires an email address + password - not a username + password. So credentials are not the same."

Login requires email.
But you still have a Username for the actual website.

I do not use my email to log into FTP so listing my email is unnecessary.

FTP server was down, thanks for the help anyway

That's not true. Requesting attention.

See test results in my last comment.