Adalm-pluto

You can replace it but Pluto does not behave just like an AWGN channel. You need to perform synchronization which is a detailed design. See here for fundamentals of synchronization https://www.analog.com/en/resources/technical-books/software-defined-radio-for-engineers.html

-Travis

My assignment is to use adalm-pluto to transmit and receive qpsk signals, I was able to set up a qpsk transmitter but I don't know how to connect to adalm-pluto, can you help me?

See here https://www.mathworks.com/help/comm/plutoradio/ug/guided-host-radio-hardware-setup.html

-Travis

What I mean is to use adalm to transmit the qpsk signal and the tx side can receive that signal instead of transmitting it through AWGN but I don't know how to do it, can you help me?

Correctly recovering a QPSK waveform (if thats what you are asking) is not a simple thing. I provided a link to a reference that goes through the process of building a receiver.

-Travis