[matter] how to erase commissioning data

I tried to build matter from https://developers.home.google.com/matter/vendors/realtek.

I could build and download firmware to RTL8722DM.
And, commissioning on matter success.

However, I cannot delete commissioning data.
I tried to download firmware again, but, commissioning data (WiFi AP and etc) remains on RTL8722DM.

How do I remove commissioning data (WiFi AP and etc) from RTL8722DM?
And, please disclose official method for building matter.
Below command does not work.

$ ./scripts/build/build_examples.py --target ameba-amebad-lighting build

I use ImageTool.exe, then commissioning data was removed.