How to encrypt usernames and passwords when using gftp with proftpd

Proftpd server settings:
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Set „Use FTP-TLS secure communications“ to „On“
Set „Require encryption on channels“ to „Control“ (This means authenticate via TLS/SSL, data is not encrypted)
Set „Verify clients“ to „Off“
Fill in the certificate settings.
Click on the „Generate a new selfsigned certificate“ apply button.
Restart the server.
GFTP settings:
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Select „FTP“ in the menu then select „Options“.
Select the „SSL-Engine“ tab.
Uncheck the „Verify SSL Peer“ option.
Click „Apply“ then „Ok“.