Hello @Emilia_Mh
The developers are never going to tell you this secret because if they tell, the popup seller sitting in the marketplace will be shutting down their shops.
Here is the code:
<div class="alert">
<meta name="viewport" content="width=device-width, initial-scale=1">
<span class="closebtn" onclick="this.parentElement.style.display='none';">×</span>
<h1>Notice</h1>
<p>
Today's Biggest News!
<br/>
<br/>
<a href='' class='close'>Details</a>
</p>
</div>
<style type="text/css">
/* The alert message box */
.alert {
padding: 20px;
background-color: #FF0000; /* RED */
color: white;
margin-bottom: 15px;
}
/* The close button */
.closebtn {
margin-left: 15px;
color: white;
font-weight: bold;
float: right;
font-size: 22px;
line-height: 20px;
cursor: pointer;
transition: 0.3s;
}
/* When moving the mouse over the close button */
.closebtn:hover {
color: black;
} </style>
Go to> Login > Stacks and Blocks > Global Region > Where You Want like (Header Search) > Add Block > HTML > Paste the Code > Done.
Thanks