Using React Dev Tools with Chrome Extension based on manifest v3

Question

I am developing a Chrome Extension based on manifest v3 and can't get React dev tools to work.

Here is what I did:

1. yarn add -D react-devtools
2. Add script tag to page of extension:

  <script src="http://localhost:8097"></script>

3. Add content security policy to the manifest file:

 "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'; script-src-elem 'self'; unsafe-inline 'localhost';"
}

Error I am getting:

Refused to load the script 'http://localhost:8097/' because it violates the following Content Security Policy directive: "script-src-elem 'self'".

I have tried all kinds of variations in unsafe-inline and nothing seems to work.