Hello @ArtemPN
Hope you are doing well.
For more information about PN7642, you can consult the PN76 family instruction manual and UM11566 PN76 family NFC open controller user manual (since this document is under NDA, it is secured in Secure Files, and you will need to request access to it).
Regarding the firmware download, perhaps you may find useful the Secure Firmware Download example "DownloadLibEx1", which is available to demonstrate the secure firmware update by using LPC55 and MCUXpresso. You can find more information on this in PN76 family evaluation board quick start guide, Chapter 4 Software.
Regards,
Eduardo.