How to make ajax output design?

Question

AJAX

I output the result through

$('.ajax-reply').html( html );

Here.

<div class="ajax-reply"></div>

How to add some design to the line above? I wanted to output through this:

<div class="alert alert-secondary" role="alert">текст</div>

But this div is added immediately before the result is displayed and it doesn't look very nice.