I know I'm really late to answer this.
You have to include Fontawesome CSS in the header.
CDN -
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.8.1/css/all.css">
If you have downloaded the source files then include as follows
<link rel="stylesheet" href="path-to-your-font-awesome-folder/css/all.min.css" />
Later you have to add the CSS as follows -
.fp-prev:before {
color:#000;
content: '\f35a'; /* replace / with \ */
font-family: "Font Awesome 5 Free"; /* here is the correct font-family */
font-style: normal;
font-weight: 900;
text-decoration: inherit;
}
if you wish to add it via <i>
tag then you can follow
<i class="fas fa-arrow-alt-circle-right"></i>
Make sure your font weight is 900.
Refer - https://github.com/FortAwesome/Font-Awesome/issues/11946
An issue was raised in GitHub for the same. They have suggested that for the solid font awesome icons the font-weight
should be 900
.
Hope this will help you all.