Hello!
By default the I2S pins are not enabled, but you can enable them by running the following commands …
$ sudo /opt/nvidia/jetson-io/config-by-function.py -o dtb i2s5
$ sudo reboot
Then you should be able to try speaker-test as follows (assuming it supports 16-bit samples @ 48kHz) …
$ speaker-test -D hw:jetsonxaviernxa,0 -c 2 -r 48000 -F S16_LE -t sine -f 500
For more details on jetson-io see …
https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fhw_setup_jetson_io.html%23
For more details on Jetson audio see …
https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fasoc_driver.18.1.html%23
Regards,
Jon