FTP "ECONNREFUSED - Connection refused by server" error

I cannot access FTP using Filezilla as I keep getting the error:

Connection attempt failed with “ECONNREFUSED - Connection refused by server”.

Ubuntu 20.04, Vultr VPS

Vultr says:
According to our network scan, port 21 is closed, which indicates that there isn’t a listening service on that port. Did you install an FTP server?

Firewall rule says:
FTP tcp 0.0.0.0/0 21

What am I missing?

Do vultr has their own firewall system? If so, try checking there too to release the mentioned port number.

Also try disabling firewall and see if it works

sudo systemctl stop firewalld 

what is the status of pure-ftps