Centering text with Photoshop Elements 2022

You can use a selection by going to Select>All, then your alignment options of Center and Middle should work.

Then go to Select>Deselect.

If you don't want to fiddle around with the text layer manually, you could also create a new blank layer and align the text with the blank layer to place it in the center of the canvas.

What Greg said.

The various Align Layer buttons are to align multiple selected layers relative to each other, not align a single layer relative to a page which is what you are trying to do.

Move the layer with your mouse and nudge it into position with your arrow keys.

You can also try the Snap To options (e.g. Snap To Grid if you're working with a grid) to see if they assist your workflow.

I don't think you are doing anything wrong.  The align options are designed to align more than one layer, not a single layer within an image.  You should turn on the Rulers and/or the Grid (from the View menu) and move the type layer manually.