Stacking Images by a novice

Hello all. I am trying to learn image stacking in preparation for the arrival of my astrophotography hardware (EQ6R + Meade 6000 115mm). I took 30 images of the moon (untracked) and have been trying to figure out how to stack them. I was hoping the software would lay the moon images on top of one another. As you can see it is not. Is there an alignment step I’m missing? Thank you for any help!

Sure. Il the alignment tab.
Make a selection big enough to contain the move of the moon on all images.
Then choose planetary algorithm.
Align and stack

Great! Sorry to ask you this…I’ve looked all over. On the Mac version where is the alignment tab?

Registration tab. On the main tabs.

Got it!! Merci!