How to take FTD rules backup

[CiscoAAA1]

Hi, 

I have taken the backup of FMC by Ssytem -> Toos -> Backup/Restore ->Firepower Management Backup  option. 

Then   I have tried to take the backup of FTD by 

Sytem -> Toos -> Backup/Restore -> Managed Device Backup. 

But I am getting a note that : Backup the firepower chasis configuration before initiating a backup of logical Threat defence configuration. 

Then I have loggein FTD chasis and System -> Configurtaion -> Local export. 

  But getting the message " Cannot export because the password of the encryption key is not set " 

Question 1.

 1. Can someone help me to know how to proceed further. 

 2. Can I backup rules and all other configuration of FTD through CLI ?  If so please share me steps. 

 3. How to restore FTD rules configuration. 

Regards

[marce1000]

 - FYI : https://community.cisco.com/t5/network-security/the-password-encryption-key-has-not-been-set/m-p/4437529#M1082439

 M.