How to hack bootloader?

The fact is that I need root rights, and for this I need to unlock bootloader. The problem is that when you choose to open it in the menu, the eternal fastboot mode starts, which does not respond to anything other than pulling out the battery. For this reason, I decided that I should try to work with the firmware myself (LG K7 X230) Link to the firmware - https://4pda.ru/pages/go/?u=https%3A%2F%2Fyadi.sk%2Fd%2FE7HdIHX43W8eAx&e=88689907

For a while I I mastered assembler, read the necessary literature, mastered debbagers (ollydebug, IDA pro), broke and created small programs,but I did not understand what I needed to do to do at least something with the firmware. And yes, there are instructions on this case on 4pda, but for me it is still mostly not clear, since there are no specifics in it. And in general, I have a request, please describe to me in detail each step that needs to be done, so that I still understand how and what needs to be changed in the firmware, what would restore the ability to open bootloader?

Ps. I applied for the issuance of a root, and questions on this topic in support of LG, but nothing more than - "This is not provided by the manufacturer" I was not told.