https://smartapi.angelone.in/publisher-login/?api_key=i089xxxx
When I open this Public Endpoint it always give 403 Forbidden for me, anything changed in this ?

I followed your official documentation

The login flow starts by navigating to the public SmartAPI login endpoint:

https://smartapi.angelone.in/publisher-login?api_key=xxx&state=statevariable
After successful login, user gets redirected to the URL specified under MyApps. With the URL we pass auth_token & feed_token as query parameters.