how to enable ftp and upload files

Use SSH instead of FTP. Look at this guide:

oh please, don’t no answer if you can specify your answer.

To transfer files from my Win7 desktop to the Ubuntu 18 droplet with the Putty pscp program I used the following command from the PuTTY directory:

//prompt
braunj@BRAUNJ-DESKTOP C:\usr\PuTTY
// command
# pscp -i id_rsa.ppk c:\usr\PuTTY\README.txt root@167.71.###.###:/tmp
// reply
README.txt                | 1 kB |   1.5 kB/s | ETA: 00:00:00 | 100%

My stumbling point was the login for the transfer. I finally found that I needed to include my key file (-i id_rsa.ppk) to authenticate myself to the server.