Wonderful short story about a sentient tank attending a comic book convention

From the start of Tank! by John Wiswell:

The tank hates revolving doors. They’re petrified watching the doors whoosh by, trying to imagine anyone getting into the convention center through these things. The curb crumbles beneath the tank’s treads, and commuters honk for them to get their back-end out of the road. Two tweens sneak around the tank’s chassis, carrying a rack of brightly colored cosplay wigs, and slip into one of the revolving glass chambers.

“Be brave,” the tank tells themself.