Not my words, Bio. Hyzon used the word 'prototype' and 'start of production'. Here is their quote from the quarterly report.
"By the end of 2023, Hyzon aims to produce and validate 25 200kW fuel cell system prototypes and have its C-sample 200kW declared. The Company is currently targeting second half of 2024 as Start of Production ("SOP") for the 200kW fuel cell system in its Bolingbrook, IL facility."