FTPS login issue on EC20

My query is I am using that all steps related to FTPS login which is mention in its datasheet . But on my side problem is after AT+QFTPOEN, it gives me “OK” only, not “+QFTPOPEN:0,0” . So what should I do , I already request for CA certification because server port is 21. So is it only happen because of CA cert requirement or it require more configuration like AT+QSSLOPEN before login, I am little bit confuse, please suggest mi proper procedure.

According to the document, there are no other operations. You need to wait at most 90 seconds to return the result code. You can try the server without authentication connection first.
Thank you