Please see below log to upload a file to FTP server.
AT+QFTPPUT=“test_my1.txt”,“COM:”,0 //All data will be saved as test_my1.txt on FTP(S) server.
CONNECT
<+++>
OK
+QFTPPUT: 0,1000
AT+QFTPLEN
OK
+QFTPLEN: 0,1000
AT+QFTPSIZE=“test_my1.txt”
OK