lrzsz binary package in Ubuntu Focal amd64

 Lrzsz is a cosmetically modified zmodem/ymodem/xmodem package built
 from the public-domain version of Chuck Forsberg's rzsz package.
 .
 These programs use error correcting protocols ({z,x,y}modem) to send
 (sz, sx, sb) and receive (rz, rx, rb) files over a dial-in serial port
 from a variety of programs running under various operating systems.

Source package