uart communication on h/w pins

I’m trying to make an application on raspberry pi which majorly has a serial function. It has to collect data and respond to it from the h/w uart ports i.e GPIO14 (TX) and GPIO15(RX).
I’ve Added a serial interface from the xojo library but it doesn’t seem work at all. The serial interface is open but nothing is echoed on the pins.
is there a way to specify the path such as "/dev/ttyAMA0 "??
I’m using a RPi 3 with raspbian stretch.
I’d really appreciate a quick response.

Thanks

In the Pi3, /dev/ttyAMA0 is used to provide on-board bluetooth.

Here is a good article that will help you disable bluetooth and reassign the hardware UART so you can use it in Xojo.

You can then use something like:

serial1.serialport = system.serialport("/dev/ttyAMA0")