Explicit FTPS: Why EC21 Mini PCIe cannot connect to FTP Server on Port 21?

I read Quectel FTPS_AT_Commands_Manual and found that at AT+QFTPCFG=“ssltype” command just has 2 values: one is FTP client and another one is FTPS client. So I wonder if I set up the module as FTPS client, it can connect to Explicit FTPS?
More information about Explicit FTPS: With explicit FTPS, before a transfer can begin, the client will request encryption information to determine what portions of the data is protected. If the client hasn’t set up these security requests, one of two things occurs – either the connection is declined, or the transfer is made insecurely using the basic FTP protocol.
Thank you so much!
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Hello imngochang, thanks for your question
AT+QFTPCFG=“ssltype” is the SSL type that the module uses as FTP client or FTPS client. If you want to log in to the FTPS server, select 1 as the parameter. For specific use of SSL to log in to the FTPS server, please refer to the steps in the figure below, thank you.

She is asking if the EC21 support explicit mode, implicit mode or both? I have the same question for EG91 module