How to inject with Manifest 3 and Private Browsing in Firefox

[IceflowRE]

As it tries to inject i get

<script> source URI is not allowed in this document: “moz-extension://a7f43bde-6c42-4a9f-b8e1-92c4fa7e2b9d/my_script.js”.

Is it impossible to inject that way?

export default defineContentScript({
    matches: ["*://example.com/*"],
    async main(ctx) {
        await injectScript("/my_script.js", { keepInDom: true })
    },
})

[Timeraa]

https://support.mozilla.org/en-US/kb/extensions-private-browsing

[IceflowRE]

That is not the problem. It works when setting manifestVersion: 2, but not with manifestVersion: 3,, then i get the error above in the console.

[IceflowRE]

It seems i forgot the web_accessible_resources.