root@sclrdev:/home/sclr/certs/FreshCerts# curl --ftp-ssl --verbose ftp://{abc}/ -u trup:trup --cacert /etc/ssl/certs/ca-certificates.crt
* About to connect() to {abc
Relating to 'SSL certificate problem: unable to get local issuer certificate' error. It is important to note that this applies to the system sending the CURL request, and NOT the server receiving the request.
Download the latest cacert.pem from https://curl.haxx.se/ca/cacert.pem
Add the following line to php.ini: (if this is shared hosting and you don't have access to php.ini then you could add this to .user.ini in public_html).
curl.cainfo="/path/to/downloaded/cacert.pem"
Make sure you enclose the path within double quotation marks!!!
By default, the FastCGI process will parse new files every 300 seconds (if required you can change the frequency by adding a couple of files as suggested here https://ss88.uk/blog/fast-cgi-and-user-ini-files-the-new-htaccess/).