I have configured a form-base authentication using Spring security. It works fine when I log in using the login form in my web application.
It also works with cURL:
You can achieve authentication/authorization in postman through various authorization types given in postman dropdown under Authorization tab.
Below is the step to use Basic Auth which by default spring security provides.
In spring security you can customize your credentials in application.properties file as given below.
spring.security.user.name=yer spring.security.user.password=galem