sudo apt-get install duck

0 upgraded, 1 newly installed, 0 to remove and 162 not upgraded.
Need to get 88.7 MB of archives.
After this operation, 211 MB of additional disk space will be used.
Get:1 https://s3.amazonaws.com/repo.deb.cyberduck.io stable/main amd64 duck amd64 8.5.6.39394 [88.7 MB]
Fetched 88.7 MB in 5s (17.9 MB/s)
Selecting previously unselected package duck.
(Reading database ... 154293 files and directories currently installed.)
Preparing to unpack .../duck_8.5.6.39394_amd64.deb ...
Unpacking duck (8.5.6.39394) ...
Setting up duck (8.5.6.39394) ...

duck, duck --help