https://youtu.be/cpX5luG7600?si=1JBEcalC8EVXvtte
https://www.gopresto.com/uploads/04830_59_869S_Eng_Web_Instructions.pdf

It requires to line the bottom of the popping bowl with Replaceable PowerCup concentrator.
Please watch the instructional video above which shows what it looks like. It is necessary item for this bowl to pop the popcorn in the microwave.
You need to purchase Popper Concentrator lining online or some of major stores (https://www.amazon.com/Presto-Genuine-Powercup-Microwave-Concentrator-0/dp/B013JKOPDA)

Hope someone could use it.
Easy pick up from near Shaver Street & Latham Street or near 20 Alvina Ave (which is harder to get to due to road closures along the part of C Street) in San Rafael.

Presto Popcorn Popper Needs Lining (5 Latham Street, San Rafael)