Hi,
The following URL does not include nRF54L15, is it supported?
https://docs.nordicsemi.com/bundle/ncs-3.0.0/page/nrf/samples/openthread/coap_server/README.html
The CLI sample is compatible, so I think it will work.
https://docs.nordicsemi.com/bundle/ncs-3.0.0/page/nrf/samples/openthread/cli/README.html
best regards,
Hiroki