Thanks @brn . Clicking on the saveToken error, takes me to this section of the extension's background.js
// tell the extension popup to update the UI
await browser.runtime.sendMessage({
type: 'synced',
token: sessionToken,
api_token: sessionApiToken,
api_engine: sessionApiEngine,
summary_type: sessionSummaryType,
target_language: sessionTargetLanguage,
});
Specifically the "await browser.runtime.sendMessage" line is highlighted. Not sure if this is what you need.