link: https://docs.platformio.org/en/stable/scripting/examples/custom_program_name.html

Sometimes it is useful to have a different firmware/program name in build_dir. The following example uses Custom options in platformio.ini and adds a project version suffix to the firmware name.

**platformio.ini:**

<code>
[env:env_custom_prog_name]
platform = platformio/espressif32
framework = arduino
board = esp32dev
build_flags =
    -DVERSION=${this.custom_prog_version}
extra_scripts = pre:extra_script.py
custom_prog_version = 1.2.3
</code>

then in **extra_script.py** (save in where platformio.ini is):

<code>
Import("env")

env.Replace(PROGNAME="firmware_%s" % env.GetProjectOption("custom_prog_version"))
</code>