I don't know what you mean when you say that "the Thunderbolt displays only have USB ports (no Thunderbolt ports)."
The 27" Apple Thunderbolt Display, model A1407, sold between July 2011 and June 2016, has two Thunderbolt connections, both of which are Thunderbolt 1 connections using Mini DisplayPort style connectors. One of the connections might consist of a hard-wired cable with a Thunderbolt 1 plug on the end.
If both connections are working and your computer has Thunderbolt and your computer supports at least two external monitors, with resolutions of 2560x1440 pixels or greater, you can daisy-chain the monitors.
If you have an Apple laptop that uses the base M1 or M2 chip (13" Air, 15" Air, 13" Pro), you have a machine that supports at most one external monitor. So you can't daisy-chain two Thunderbolt Displays to it, and expect that to work.