2 Nucleo as slave to Modbus master

[Dadhichee_19]

I want to connect 2 Nucleo F103RB as slave (2 Nucleo slaves) to one master (PC for now) over Modbus (RS485). how can I do that? Please note I am new to STM32, so I have limited knowledge.

P.S. I have connected one master (PC) and one slave (Nucleo) but cannot find answer how to connect with 2 Nucleo over one master.