I agree with Carlo and dmv18 since it says MOST RECENTLY issued passport; however, I was also confused since the I-765 Instructions say the following:

"Passport and Travel Document Numbers. If you used a passport or travel document to travel to the United States, enter
either the passport or travel document information in the appropriate space on the application, even if the passport or
travel document is currently expired."

Carlo,

I also put the expiration of my most recently issued passport (2).