I personally wouldn’t rely on Cookies in a Capacitor app for authentication. See my post over here - Server set cookies not working on Capacitor iOS - #2 by twestrick
Since that post though, the Capacitor team improved (or released?) the native Cookie plugin which should greatly help those that need to use cookies. Though not mentioned in the documentation, Set-Cookie was added in v4.6.0.
- cookies: Use Set-Cookie headers to persist cookies (57f8b39)
You might need to use the native HTTP plugin too? I am not sure. Hopefully someone else can chime who has a working app using the Cookie plugin for auth. I am just giving my two cents because I’ve seen so many posts here about Cookie issues where they don’t seem to be reliable for a mobile Capacitor app 