Embed a map with satellite terrain active (iframe)

Yes, it is possible, but you need to change it in MyMaps before you create the embedded <frame>. See: http://www.geocodezip.com/SO_20220206_embeddedSat.html

The top map is your original, the bottom map is a copy with the base map changed “satellite”.

To change the base map, click on “Base Map” in the left hand menu:

Then choose the image of the satellite tiles:

Then share and capture the new embedded <iframe> with a potentially new URL (might actually be the same).