Alert message validation - Test Automation (Selenium)

Good Morning! I'm catching a lot in a setting. Could you help me?

Scenario: I perform an action. It is a temporary (alert) message on the screen. After a few seconds, disappear! What I need: Perform a message validation on this temporary alert.

Below is the location of the element:

**strong text**<div id = "alert-message-20190726103017" class = "top alert danger alert alert fired";>
<button type = "button" class = "close" / button>
<i class = "fa-exclamation icon" / i>
"Invalid username and password" / div>

Can someone help me? Please and thanks!