Filter div elements based on user input REACT

I've to filter the div elements obtained from a database based on user input. This is a list of users of a chat and I want to show only the div of the user written in the input. I've tried several solutions on the site but they don't work in React. I'm getting mad. Ideas? Thanks so much in advance.

<div class="sidebar__chat--container">

 <a class="link" href="/room/A">
 <div class="sidebar__chat">
  <div class="avatar__container">
  <img src="1" class="MuiAvatar-img">
  </div>
 </div><div class="sidebar__chat--info">
  <h2>Mario</h2>
 </div>
</div>
</a>

<a class="link" href="/room/B">
<div class="sidebar__chat">
 <div class="avatar__container">
 <img "2" class="MuiAvatar-img"></div>
 </div>
 <div class="sidebar__chat--info">
 <h2>John</h2>
 </div>
</div>
</a>

   </div>

<div className="sidebar__search">
 <form className="sidebar__search--container">
 <input 
 placeholder="Search for users"
 type="text"
 id="search"
/>  
</form>
</div>