OK. I think I found the documentation for Mass-storage mode to update the firmware.
https://www.nxp.com/docs/en/application-note/AN13134.pdf page 54.
However, I have no idea which file I should put.
[kenny@MBP PN7642_FW_v02.02]$ ls -l
total 1840
-rw-r--r--@ 1 kenny staff 207995 Oct 10 2023 NXP_SLDA.pdf
-rw-r--r--@ 1 kenny staff 115 Oct 6 2023 PN7642_Default_AESChipKey.txt
-rw-r--r--@ 1 kenny staff 5702 Oct 6 2023 PN7642_Default_App_RSAKey.pem
-rw-r--r--@ 1 kenny staff 55036 Dec 15 2022 PN7642_SecureFW_SCR.pdf
-rw-r--r--@ 1 kenny staff 40114 Oct 9 2023 PN7642_v02.F2.esfwu
-rw-r--r--@ 1 kenny staff 1770 Oct 10 2023 ReadMe.txt
-rw-r--r--@ 1 kenny staff 306336 Oct 9 2023 phDnldNfc_UpdateSeq_v02.02.c
-rw-r--r--@ 1 kenny staff 256876 Oct 9 2023 phDnldNfc_UpdateSeq_v02.F2.c
-rw-r--r--@ 1 kenny staff 47842 Oct 9 2023 pn7642_v02.02.esfwu
-rw-r--r--@ 1 kenny staff 232 Oct 6 2023 version.txt
I assume that should be a bin file format.
Here is the screenshot when board operates in Mass-storage mode.

--Kenny