Atmega328p lock Bits

hello guys
I'm new to this so plz some help
after days of reading on forums & the datasheet I couldn't find the lock bit I should use to protect my code from being read
I can read with avrdude but I don't know what to set as lock bit (LB)
i read alot about damaging the chip by setting wrong lock bit
in the datasheet i have downloaded of atmega328 i couldnt read about fuse bits & nothing clear

any help will be appriciated

Are you trying to do this through the bootloader? The bootloader can does not change or read the fuse bits.

If using an ISP tool then tell which one.

I have tried using avrdude through boot loader & it reads bit lock as 0x00
i can try in avrdude usin bootloader & i can do it in isp
so plz guide me to the correct bit to lock the chip reading
I can simply test it by lock the chip & read it & try to reprogram it again

Again... the bootloader can does NOT change [update: or read] the fuse bits (or the lock bits).

Fuse setting I use on 328p befor I put a bootloader in it

After I put the bootloader in (prevens bootloader from changing itself)

I don't use the other lock features, and it does not sound like they do what I would want (e.g. I don't want a brick). If you set Mode2 or Mode3 it may be that HV programing can erase it but I have not tried that.

Turning off the SPM instruction for Application memory seems like it will stop the bootloader... but what use is that?