use serial ports on colibri imx6 evaluation bord

I am using the colibri imx6 evaluation card with the linux test image. I created a C++ program to test serial interfaces. I can’t use the physical serial ports on the card (one of these serial ports is used for debugging the card). but how to use others?. on the other hand everything works fine with a usb/serial converter connected to the usb. can anyone help me?
can you confirm the name : /dev/ttymx0 /dev/ttymx1 /dev/ttymx2 ?

thank you very much

The Colibri Evaluation Board features three serial ports accessible through its connectors. Colibri UART_A is available as RS232 on the lower part of the X25 connector or via a Serial-to-USB converter on X27. Colibri UART_B can be found on the upper part of the X25 connector. UART_C is accessible at TTL levels on X12, alongside UART_A and UART_B. For detailed information, please refer to the Colibri Evaluation Board datasheet and schematic.
Additionally, consult the following document for more insights: