Ujjawal_02 That has nothing to do with “high end pc” :-) Alternate A2DP implements LDAC for Windows (in its own BT driver stack). At the end, LDAC is just a codec (format) protocol using BT as transport layer (avrcp).
In my understanding, LDAC has to be activated on the Nothing Headphone itself, but with the iPhone App this is not possible, therefore the Headphone propagates (maybe) only SBC and AAC. But I am not sure - I was also not able to use LDAC with A2DP. Have no Android Phone to try LDAC out…