Go to the file location:
Steam\steamapps\common\Left 4 Dead 2\left4dead2\cfg

You open the file: addonconfig

And you set all the values ​​to 0. Save and close the file.

And then you play the versus mode on a local server to use the mod scripts.

Note: I recommend using this mod so that the bots can play alone without losing the server due to lack of human players and to be able to improve the survivors and infected bots.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=655424673&searchtext=competitive+bots