Hi @chen!
The FiRa configuration to be used with Nearby Interaction is exchanged between the iPhone and device using two messages, “Accessory Config Data” and “Apple Shareable Config Data”. The Accessory’s preferred configuration has to be set using the “Accessory Config Data” message, but only very few parameters can be set, like the device role and update rate.
After receiving the “Accessory Config Data”, the iPhone will send the final configuration to be used.
If you use a different configuration or modify it yourself, TWR is likely not to work.
Kind Regards!