signInWithCustomToken([...]) failed: FirebaseError: Firebase: The custom token format is incorrect. Please check the documentation. (auth/invalid-custom-token).
at z (content.bundle.js:2:10321343)
at I (content.bundle.js:2:10320803)
at V (content.bundle.js:2:10326216)
at async Z (content.bundle.js:2:10326332)
at async lt (content.bundle.js:2:10362906)
at async U.updateToken (content.bundle.js:2:11564428)
at async U.start_annotator_app (content.bundle.js:2:11563084)
Loading a private map (e.g. https://beta.onlinewardleymaps.com/#private:64ef83a2-4e81-45e5-a1af-5d2403fb909a) results in this error in the console: