Neither petri dishes nor flasks will turn living bacteria into the dormant spores required for an inhalation attack.
Thus, you are missing the equipment to go from bacteria to spore.
I don't think it's a good idea for me to educate you on basic microbiology, but I'll respond just this one last time.
The growing bacteria in a Petri dish will continue to grow as long as they have food. When they run out of food, they'll form spores and become dormant until they detect the presence of food once again.
In fact, because Bacillus anthracis bacteria are incapable of movement, the bacteria in the middle of a colony will run out of food pretty quickly and form spores while the bacteria at the edge of the colony will continue to grow and reproduce.
When all the food is gone, every bacterium that was able to do so will have turned into a spore.
It all happens in a Petri dish in a couple days.
Click HERE for an illustration of this process which I created a few years ago.