I can't use Corruption Altar on Console

There is no UI element to show you which button to press to use the altar and following tips of other thread (https://www.pathofexile.com/forum/view-thread/3100454) don't seem to work

If you're talking about the corruption altar in the Vaal Ruins (Act 2), you can only corrupt equipment and jewels there. Skill gems sadly are excluded from that one.

That's why you don't see the "A to corrupt" prompt when hovering over those.