To capture FTP packets in Wireshark, follow these steps:

1. Start Wireshark and select the network interface you want to capture the FTP traffic on.
2. In the Wireshark menu, click on Capture -> Options.
3. In the Capture Options window, select the network interface you want to capture traffic on and click on the Start button.
4. Filter the packets to only show FTP traffic. You can do this by typing “ftp” in the filter bar at the top of the Wireshark window.
5. You should now see all the FTP packets that are being transmitted on the selected network interface.
6. If you want to save the captured packets, click on File -> Save As and choose a file name and location to save the capture file.

Note: In order to capture FTP packets, you should have access to the FTP server and client or be in a position to capture the traffic on the network. Also, keep in mind that capturing packets on a network without permission is illegal and may result in serious consequences.