vue3에서는 devtool beta버전을 설치해서 사용하라고 되어 있음.
Devtools Extension
We are working on a new version of the Devtools with a new UI and refactored internals to support multiple Vue versions. The new version is currently in beta and only supports Vue 3 (for now). Vuex and Router integration is also work in progress.
For Chrome: Install from Chrome web store(opens new window)
Note: the beta channel may conflict with the stable version of devtools so you may need to temporarily disable the stable version for the beta channel to work properly.
For Firefox: Download the signed extension (opens new window)(.xpi file under Assets)
https://v3.vuejs.org/guide/migration/introduction.html#vuex
devtool beta :: https://chrome.google.com/webstore/detail/vuejs-devtools/ljjemllljcmogpfapbkkighbhhppjdbg/related?hl=en