Freedopop plan on Walmart was discontinued in late 2022. It is never coming back.
There however could be a new Freedompop plan as somebody has seen the sim at Target. Apparently, the plan uses the AT&T network and offers 100 minutes, 100 texts, and 100mb per month for free. Price at the Target store was $4.99.
Right now, getting this new plan is unverified as the person could not activate the sim and get the new amount minutes, texts, and data. He could only signup for the old AT&T plan that was essentially worthless.