DEMO
https://evofan.github.io/pixijs_dragdrop_v4/
reference
Examples for PixiJS version: v4 Dragging
https://pixijs.io/examples-v4/#/interaction/dragging.js
【PixiJS】ポインター・マウス座標取得【相対・絶対】 - Qiita
https://qiita.com/kerupani129/items/099c7143b59648ce9344
Get pointer / mouse coordinates (Relative / Absolute)