Hi Tuan,
Currently, today you can not publish a Chrome extension manifest v2 to the Chrome web store, only update it. And new developers can only publish the manifest v3 Chrome extension at the Chrome web store.
Changing the manifest version from 2 to 3 will not solve this issue, because it also needs more code updates than that. For example, the background page should become a service worker, the browser button becomes an action, etc.
After analyzing this further, I see that the developer of that Chrome extension does have an Open-Source repo on Github.
https://github.com/Aioros/livehostsI did send just an email about this issue to that Chrome extension developer (using the email from his Github profile page). So I hope he reads this.
Thanks,
Stefan vd