This may be what you are refering to.

https://www.ir.plugpower.com/press-releases/news-details/2022/Plug-Supplies-Walmart-with-Green-Hydrogen-to-Fuel-Retailers-Fleet-of-Material-Handling-Lift-Trucks/default.aspx

LATHAM, N.Y., April 19, 2022 (GLOBE NEWSWIRE) -- Plug Power Inc. (NASDAQ: PLUG), a leading provider of turnkey hydrogen solutions for the global green hydrogen economy, today announced an agreement with Walmart Inc. (NYSE: WMT) for an option to deliver up to 20 tons per day of liquid green hydrogen to power material handling lift trucks across Walmart distribution and fulfillment centers in the U.S., marking an additional step the retailer is taking to incorporate alternative zero-carbon energy sources throughout Walmart’s supply chain. This is one of the first green hydrogen supply contracts for Plug, validating the company’s multi-year investment in its green hydrogen network.