How do i pass custom action data gotten from login screen to modal screen

I have a custom action created on login page to call my API for login which returns successful login or failed login as message on click on the submit button after which will link a modal screen to display the login message, i have tried to get the message displayed on the modal screen but to no avail. how do i achieve this.

If you create a LoginMessage property on the Users collection, you can have the custom action output Update > Logged in User > LoginMessage. Then the modal can display Logged in User > LoginMessage.