H480 has u-blox MAX-M8Q which doesn't support RXM-RAWX. The M8P and M8T do.
If it had M8N then maybe could be upgraded to M8T. So no luck.
You need to attach separate GNSS logger with antenna based on M8T or other rawx capable to do PPK.
What you could do is connect to UART of GPS module and...
