I created a Spring boot application and hosted it in Catalyst Appsail and since I needed a to have a user database to my application so I added catalyst authentication to my spring boot application the catalyst login iframe didn't work when I test in local using catalyst serve but it didn't work.
I deployed the same application to development environment and when I accessed the URL the login iframe loaded properly. I don't know why its not working in local environment.
Attaching screenshots from the local environment for reference
You might face this issue if you haven't updated the CLI to the latest beta version which you can do by running the below command in Administrator mode
npm install -g zcatalyst-cli@beta
Once updated, you can add the below two key-value pairs in your appsail folder's app-config.json and try using catalyst serve again which should resolve this issue of catalyst login iframe not loading
{
"catalyst_auth": true,
"login_redirect": "/app.html" //Your redirecting html page.
}