For an Atomic site, there is a /hosting-config/:site page available (accessible also from Settings > Hosting Configuration in sidebar) and it contains a card for opening phpMyAdmin:
How the “Open phpMyAdmin” button works is that it first issues a POST request to public-api to retrieve a token, and then opens a wordpress.com/pma-login?token URL in a new window.
It’s the POST request this PR is migrating from a data getter to a simple wpcom.req.post request.
How to test:
Verify that the flow I describe above works for an Atomic site: clicking the button should retrieve a token and open a phpMyAdmin for the site in a new tab.
Unfortunately, no screenshots were provided by the developer.
