I'm looking for the ESPG code of this projection.
1 Answer
It looks like a Peirce Quincuncial:
https://en.wikipedia.org/wiki/Peirce_quincuncial_projection
I don't see it in the EPSG registry, but you could make up a PROJ string or WKT for it from the examples here:
https://proj.org/en/9.2/operations/projections/peirce_q.html