I see, you put it in your auto exec.
You see, when you try to reload or addbots while in the menu, it doesn't work.
Simply start up the server, bot_enable should be 1 with your autoexec,
and then either through the console (LAN/WAN) or in your in-game console(non dedicated)
then exec the addbots.
And Term, the site is spreading lies/misinformation:
/addbot <type> <level> <team> <ping> <server nick>
It's not ping, IT'S MS DELAY BETWEEN CONNECTING AND JOINING THE BATTLE.