opt header file

Hi:
when I read the AN_B_001, I found a in section3 I did understand it. the cute is following :

"DevMode will be entered when the OTP header contains a value zero at the first two addresses,
when read by the CPU. This implies that the OTP is not programmed and the DA1458x should switch
to the DevMode, so that users get access to download code from external devices into the internal
SRAM (SysRAM). "
where can I found the OTP header ,if the first address didn't contain value zero ,how can i modify it ?
thks