Remote FTP: Connection failed Error: self signed certificate

Hello,
I tried to connect via ftp using atom and i go this error: Remote
FTP: Connection failed
Error: self-signed certificate

I tried to find what this is and i found this link: https://flight-manual.atom.io/faq/sections/i-m-getting-an-error-about-a-self-signed-certificate-what-do-i-do/
which suggests that i use this command:

apm config set strict-ssl false

but i don’t know how to use it. Where do i add this command?

thanks