I tried inserting hackablelockedcrate.requiredhackseconds "300" into my serverauto.cfg file, but everytime i restart thte server, it dissappears. I also entered it in the in-game console, and thats how i made it work for every time i start the server.

You should put it in server.cfg

serverauto.cfg is automatically generated, you should never touch it.

JimDeadlock

You should put it in server.cfg

serverauto.cfg is automatically generated, you should never touch it.

should i put " around the number 300 or leave it without them? I saw another post about a simmilar suject and it didnt have them.

Quotes are only strictly necessary when there is a space in the text, but in this case it doesn't matter, with or without will work.