Lovely Craft — Piston Trap Achievement Guide

: To earn this achievement, repeatedly place ender beads into the character's stomach rather than the designated holes. The beads will disappear and respawn; doing this multiple times triggers the achievement.

Even after you craft the piston, the achievement may not appear. Here’s why: lovely craft piston trap achievement guide

You can also use a trap:

To unlock the hidden achievements in Lovely Craft: Piston Trap : To earn this achievement, repeatedly place ender