Font Awesome is a great font containing a lot of icons to use on your webpages. You can use 2.009 free icons, and with a Pro plan you even have 16.083 icons at your disposal.
https://fontawesome.com/search?m=free
Usage example:
Head section:
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.1.1/css/all.min.css" integrity="(....)==" crossorigin="anonymous" referrerpolicy="no-referrer" />
Style:
.knop {
margin-top:10px;
width:80px;
height:40px;
border-radius:5px;
text-align:center;
padding:0px;
color: #0328fc;
border: 2px solid #0328fc;
cursor:pointer;
font-size:1.8em;
}
Body section:
<button class="knop" type="button" title="Ga dag terug"><i class="fa-solid fa-backward-step"></i></button>