Hello and welcome,
Should add that the map above is the Ingress Intel map, with an overlay extension that allows S2 cells to be seen. You do need to have an Ingress Prime account in order to access the map.
There used to be an app for the Spatial/Lightship map, but Niantic has retired it for Android as of November 2024, and I believe it’s soon to be retired for iOS. I thinking that the video you watched may have some outdated info in it. Here’s the discussion about this app’s deprecation, which includes a link to a news post from Niantic about it.