We are presented a challenge.zip containing

home/
    ctf-player/
        drop-in/
            flag.png

as well as a remote shell printing a qr code. The same QR code is also found in the flag.png inside of the challenge.zip and on the remote shell

$ ls
flag.png

To decode QR codes from an image we can use a command line tool like the zbar bar code reader. Fortunately this tool is already installed on the remote shell so we simply call it and get our flag

$ zbarimg flag.png
QR-Code:picoCTF{...}