https://www.geeksforgeeks.org/html-window-alert-method/

window.alert("Hello world!");
alert("Hello world!");

Hello

Please refer below link.

https://www.w3schools.com/jsref/met_win_alert.asp

Thanks

Hi Harshita Singh,

Display an alert box:

alert("Hello! I am an alert box!!");

Try it Yourself:

• https://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_alert

Hope, this will help you!

The Window Object
The alert() Method

Click the button to display an alert box.

Try it

Using javascript you can do it easily.

The Window alert() method is used to display an alert box. It displays a specified message along with an OK button