Places to fire ceramics (rent kiln space)

Hi artsy BWT! I’m hobby ceramics artists through many past workshops and hikes have made some pieces out of gifted natural clay or wild clay and have been looking for a good kiln space to fire them. I don’t know the exact composition on the clay bodies of my pieces (especially the wild clay ones), and I’m looking for a place that’ll let me rent kiln space by item, weight, or square inch.