To work, you need a programmer to connect the board to the computer.
At the moment, two programmers devices are offered with a connection via a USB port and with a connection through a COM port.
USB Elnv Prog - convenient, fast, stable. Ready version, affordable price. DISCONTINUED FROM PRODUCTION.
USB FT232RL chip - analog of discontinued USB Elinv Prog.
COM diagram - the simplest scheme is assembled in a few minutes. Requires a system COM port.