How to Create ssl certificate and key required to setup FTP over SSL/TLS?

how to Create ssl certificate and key required to setup FTP over SSL/TLS ?

Refer this link:
https://www.tecmint.com/secure-vsftpd-using-ssl-tls-on-centos/

Do we need to store everything in QBox directory ?

@mukulvashishtha
Not necessarily, but that would be easier to manage