Base on NExt Doc: "
While assetPrefix covers requests to _next/static, it does not influence the following paths:
Files in the public folder; if you want to serve those assets over a CDN, you'll have to introduce the prefix yourself"
https://nextjs.org/docs/app/api-reference/config/next-config-js/assetPrefix
Idea
https://nextjs.org/docs/app/building-your-application/configuring/environment-variables