Head to: https://archive.ph/

Copy the URL of the paywalled article into the "I want to search the archive for saved snapshots" textbox! [blue, bottom box]

Can also archive an article for others to use if you copy a non-paywalled article into the "My url is alive and I want to archive its content" textbox. [red, top box]

-- Editing to add -- can also just append "archive.is/" to the beginning of the URL and it will take you to the list of non-parywalled, archived versions of the article

[https://www.theatlantic.com/science/archive/2024/01/fetal-maternal-cells-microchimerism/676996/] becomes

[https://archive.is/www.theatlantic.com/science/archive/2024/01/fetal-maternal-cells-microchimerism/676996/]