Check you are signed in, in the same browser. The editor extension gets its token from a flowky.ai session. If you signed in elsewhere, or in a private window that has since closed, there is no session to read.

Check the token has not been revoked. Settings → Security lists active tokens. If you revoked one and did not reconnect, the extension is holding something the server no longer honours. Signing in again issues a new one.

"Could not establish connection. Receiving end does not exist." This is the browser panel talking to a background worker that the browser has shut down to save memory. It is expected, not a fault: the browser stops idle workers and starts them again on demand. The panel retries, and the action goes through on the retry. If it persists across several attempts, reload the extension from the browser's extensions page.

The bridge between browser and editor needs both ends running and the pairing code entered once. If the editor was restarted, re-open the panel to re-establish it.