In the kitchen, spices must always be tidy and handy!
Each module can contain 8 jars 46x46x90 mm, with a square or round base.
Each compartment has a slight inclination backwards to facilitate insertion of the jar.
I bought these containers:
https://www.amazon.it/gp/aw/d/B0CCTPZQR1?psc=1&ref=ppx_pop_mob_b_asin_title

No supports needed.