Hi @RaspBeginner,
the relays are connected via I2C expander MCP23008. You can communicate directly with the chip by using e.g. this tutorial: https://learn.adafruit.com/using-mcp23008-mcp23017-with-circuitpython/python-circuitpython
Or, which is more preffered way, to use our API called Evok: https://github.com/UniPiTechnology/evok. With this API, you will get a uniform access to all IOs across all our products.
Best regards,
Martin